There are no hard and fast rules when it comes to poetry, but I think that a few little things will make it stronger ...
Sun's rising up outside
Light never existed
I'll paint my world black and red
Bit my fingers off, cut off my vein, my eyes won't close
Why can't I do it?
Change "bit" (the past tense) to "bite" (present tense). The verbs are already jumping a bit in this stanza, and the past tense makes it jumpier.
How could you stabbed me
This is another place where the verb "stabbed" doesn't fit well. Change it to "stab" instead.
There's some nice imagery here and you have a good sense of word play.