Im not going to bash your poem, because its about cutting, I went through all that stuff too.
But I would like to stay that it is a very steriotypical angst poem. Stanzas and clear cut rhyme. Angst and anger, cutting and mutilation.
I have hope for you though. Try to branch out in writing, try free verse instead of stanzas, maybe even forget rhyme. You have potential. I only urge you to try. If you are comfortable withyour writing though, you do not have to take my advise, it is an opinion, very freely given. I hope I havent taken up too much of you time babling. Good luck in the future!