closed lids

[Municipal Alchemist]

Closed lids

It darkens when you leave the room; in me,

and though the sun's light beams through latticed blind, I think you're going for a double meaning in "light," but this part totally destroys the meter for me (light is stressed and should be unstressed, "sun's" is a heavy word). I think that can be useful for emphasis, but it's too much here imo
I feel a colder singularity, Maybe no comma?
that's limp and lays impotent in my mind. the stresses are switched around in "impotent"
The bottom sheet lays on the hardwood floor;
it holds the tears that no one saw me shed. this line feels a little cliche, but i do like the image
I sleep with one eye  looking at the door, period changed to comma
and hope you'd  knock, but no, the door is dead. comma added

It's hard to resurrect and shine like spring Not sure that resurrect fits here, what is being resurrected?
when strings lay cut and all one's guilt ebbs out. I'd prefer "flow" to "ebb"
When one is lost and can no longer bring
a friendship to the fore, except in doubt, period changed to comma
It's then she knocks, unlocks to sidle in I love "sidle"! great word choice
and drag me back; her warmth destroys my sin.

I love formal poetry, and I especially like somber sonnets like this, where the content disrupts our expectations from the form. It feels a little rough; the meter is off in places, and a couple rhymes feel sort of forced, like "bring" with "spring," and "sin" with "in." When I was reading, the tone sounded like you really want the words to flow along the iambs, so I'd be really hesitant to disrupt the meter unless the moment is really important. I'd even opt for slant rhymes over awkward meter, it feels like the most effective poetic device here.

Content wise, I really enjoy the contrasts of presence and absence, and relating it to warmth and coldness. It's a terrific theme, and I think you're really focusing in on a powerful poem. It feels like there are undertones of sadness even beyond the (implied) lover's absence, and I think that could be brought out even more. "Sin" at the end feels like its referencing something that isn't quite mentioned previous, so as the last line of the heroic couplet, it feels out of place, which is probably why it feels like a forced rhyme to me. What did the speaker do that is erased so easily by this lover? Though I do like a little mystery there so don't give too much away! (sorry about the contradictory advice, but something to think about).

Great start though! I'm excited to see where this goes!