You definitely were having a hard night the night you wrote this.  There is no question that thoughts and emotions were bombarding you all at once.  There is confusion after a break up and this piece certainly displays that.  I hope you are doing better.

You mentioned that this was the result of what happened after 4 days of no sleep.  When you go back to edit this, I think it will be great to break these thoughts down as Day One, Day Two, etc.  Was there lack of sleep because you knew the breakup was coming.  Was the breakup responsible for the lack of sleep AND the drinking? 

The second thing I would say is keep the lines short since all of that stuff is happening one thing on top of another on top of the other.  Here's an example:

my moldering furnace of day dies

my thoughts consist of eyes and smells

and old sounds breathing slow,

I remember, I thought, remember this,

because this is perfect

now that perfect is stone slung over heart heavy,

walking: chore and labor, and feet feel sore

across blacktop mountains of fog.

and I remember you said that

I moan in sleep,

you were never peaceful then

when, sleeping, I watched through closed eyes of dreams

perfect nose felt warm body heat, cold toes kept warm,

backs and shoulders and hips for 18 year

old hands

Everything is coming at us at a fast pace. Shorter sentenses denote the speed.  Keep us on that fast track!

That's all I have. Nice look into the agony of a breakup and all the emotions and thoughts that come with it.

With this one, I really have to start with the title. Hands are precious to us. A human can do with just one kidney, eye, or nowadays with just one foot, but few people can image losing even one of their hands. Moreover, hands can tell a lot about a person, for whatever we do will leave a mark on them.

Now, I'll for once try to go through the poem little by little.

21 year old hands look gnarled in blue computer light I listen sad songs,

I know you have edited this only very little, so I won't dwell on the punctuation that seems to be missing, but I think it would be reasonable to put out the latter part of this verse sounds strange, and is possibly missing a "to." furthermore, I think splitting this verse in two might be a good idea.

feel almost hysterical at night

jealous, confused, hungry, twisted, sick

These two verses work very well together. The swift succession of 5 words with such strong negative connotations conveys a great impression of hysteria.

my moldering furnace of day dies

As much as I like the image of a moldering furnace, I can not help but wonder if this might simple by a typo and should read "smoldering."

my thoughts consist of eyes and smells and old sounds breathing slow,

The combination of a sensory organ with two sensory impressions is rather peculiar, and certainly draws attention towards the eyes, though they are rivaled by the personification of sounds, which might represent his memories of her still being alive.

I remember, I thought, remember this, because this is perfect

Ah, we peek right into his head, no? The interjection gives it away, and the repetition of "remember" emphasizes the effect, and echo of his own thoughts in his mind.

now that perfect is stone slung over heart heavy, walking: chore and labor, and feet feel sore

I'm not sure if using and adjective as the subject of this sentence adds or detracts from the effect. However, the whole verse is a bit long, and tedious to read. It does feel like a "chore and labor,"

across blacktop mountains of fog.

This is an interesting image, but I unfortunately fail to attach a meaning to it. However, that might be the result of not forming the right connection to the previous verse.

 

and I remember you said that

I moan in sleep,

Unexpected line break there; this creates a bit of tension, the wish to find out just what she said; more so than the expected line break of  "you said/ that I..." would have.

you were never peaceful then

Oh, this could have so many different meanings attached to it, with "then" remaining blissfully undefined, and "peaceful" still lost in the no man's land between definition and vagueness.

when, sleeping, I watched through closed eyes of dreams

Supposing this verse forms a unit with the previous, it defines the formerly vague time, but at the same time faces the reader with a seemingly paradox situation. I perceive it as him seeing her in his dreams, where she is slightly different than in reality, and this perception of her might actually be the cause of his moaning, whose emotional nature is not defined.

perfect nose felt warm body heat, cold toes kept warm, backs and shoulders and hips for 18 year

old hands

not gnarled,

but still in blue computer glow.

Perhaps the first of these verses should be separated further, but breaking between year and old should be preserved. Throwing two such short line at reader draws the attention straight to them, and placing "old hands" on their own, separating from the 18 that identifies them as actually still young, and possibly hers, as his were referred to as 21-year-old above, allows them to signify an age that is not physical. You emphasis that the age is not physical by stating only the glow of the computer glow creates that visual impression, but in my opinion, a computer glow speaks of loneliness and isolation, nobody there to share your time with but a cold machine.

I remember your body was an old house lived in for years,

I knew it in the dark and never stumbled over stray afterthought furniture.

Very nice metaphor here. Is it just me, or do these verses have a quite open sexual undertone?

I remember your mind alive with questions problems singing and wine.

I remember your soul stubborn unbending will bleak beautiful blaring love moments

The anaphora here works quite well, but the verses might be a bit long, and suffer greatly from the lack of punctuation. "Singing and wine" were really unexpected in that enumeration, which makes them thought-provoking. However, the "blaring love moments" really fall out, and I can not fit them back in, as little as I can fit the "bleak" with any certainty to them or her will.

 

and retreat into confusion,

and heartfelt harmonica howls at distant microphone madness

 

Confusion is not a surprising 'refuge,' whereas the "harmonica howls" are fresh to me, and the "microphone madness" fits well with his own confusion.

 

I remember you knowing so much more, so mature, and yet understanding nothing but yourself.

I remember your drug discovery watch your speed, and my bones on yours became a bad innuendo,

and afternoon meant afternoon.

Again, these verses may be a bit long, but the anaphora emphasizes the essential change perceived in her and their relationship nicely.

.I remember you could live for days eating nothing but simple understanding and hummus.

Another nice illustration of the basic change in her, though mostly by virtue of using "remember you could."

but acoustic bass barriers broke into me long before I said, sad,

cinema seeing was never enough, knowing you so well, knowing no door alone,

 

I cannot make any sense of the "bass barriers" by themselves, but somehow they add to the effect of these verses, as he breaks through a barrier in uttering those words and pinning a problem down. "Knowing no door alone" is yet another piece I must confess I fail to grasp.

knowing airplane peanuts, plain sand, sun, stone paths to palm tree desolation,

long road sunglass photo shoots in Ybor City, knowing that music was just music and never

enough,

This now makes much more sense, and the "bass barriers" from before become clearer again. A flight followed by a photo shoot; he was with her, yet she could not understand his passion for music, just a string of notes to her rather than a gift of calling emotion. It was simply not "enough" for her, which is punctuated sharply by that word standing alone in its own verse.

knowing hands and salty eyeball and empty awkward clammy laughing

at bitter night cigarette smoked carelessly of lungs,

Yet more anaphora, drawing the verses close together, at the same as they highlight the distance growing between them. Does that count as a form of irony? The second verse is very evocative as well, the bitterness of the cigarettes and carelessness of mistreating a vital organ like that mirroring the bitterness and carelessness growing between them.

knowing gray morning return to snow nicotine craving iron lungs longing for fresher air.

I think this verse really needs to be separated, if not into two verses, than at least with a comma; at least assuming nicotine is meant to relate to "craving lungs" and not snow.

knowing last looks and touches and tears and fat household Buffalo-bound cats causing

Yet again you fool our expectations by concluding an enumeration in the most unexpected way.

later allergic reactions necessitating endless Benedril.

Tragically comic, this verse. His emotional pain is mocked yet somehow mirrored by his allergy, and neither seems to go away, no matter the medication.

knowing glances going bankrupt with distance,

I really like this image. Aptly relates an abstract we all know, emotion, to an object we all know, money.

knowing Providence no longer welcome haven and endless enthusiasm and rest of soul and body,

I think this sentence needs a bit of punctuation to become immediately accessible to the reader.

knowing faceless discoveries of absence and unaware and certain now of no return,

This line as well might lack a comma. However, the combination of faceless and absence is great, as is the paradoxical state of being unaware and certain, which seems to me closely related to the state of denial and certainty.

knowing the phantom limbs of soul’s light tingle, gone now,

A fine description of that peculiar sensation of two souls meeting and brushing against each other.

and, sleeping, I watch with intense attention the blue glow screen for old shadows of nighttime

confessions

seeing only pain blue self, reflected.

The first verse here might need separation. His sleep seems to be less physical now, but metaphysical, his mind resting as his old confessions replay in his mind, their importance stressed by the word "confessions" standing on its own.

seeing only pain blue self, reflected.

A verse with beautiful double meaning. On the one hand, there is his physical reflection on the blue screen, but on the other hand, thinking about what has happened, he reflects on what he has done any on his sad (blue) self.

Should it read "pained blue self," though?

On a final note, I like the way you use alliterations in this one to draw the attention to certain, often unusual, phrases.