You have all the makings of a great poem, there's just a few things I would suggest you change to improve the overall "flow" of your poem.

The reflection of my face in your glimmering eyes(.)
I can't help but turn away. (Change lines here) A face of pain and shame is all I see in (a <- you could change it to "the") mirror.

Why can't I do anything right? Why do I have to be a mistake? I stare into the eyes staring back in the mirror and cry. (change lines) Not stopping myself I take a knife and press it to my heart. Will I really do it? Will I see the light of tomorrow? I ask myself(,) what there is to live for anymore(?) (and <- Take out) I puncture a slit in my skin(.) I watch the blood dripping and think of you. You messed up my life to where I can't live another day.

There are just a few things I personally think would make your poem flow better. You have some great ideas, and overall it was a great poem. 5/5

This is really good.. and yeah, i'm soo with ginger.. perhaps use comma's instead of periods.. but just a thing.. anwayy, your poems don't suck.. their acutally really good... 5/5 way to go.. please ehck out a few of my poems!
-Marina
p.s.. i've written a few about my son... you could prolly figure out the name iof you read the ittles. theres like 3 about him.