One word, cliche, apart from the end, advising against suicide, this exact insight on life's hopelessness is overdone and under-displayed. You're rhymin' is fine, if basic, your emotions are apprent but not too deep...
Simply feel, add a new spin on the idea of suicide, don't use the jaded ways of others, and if you wrote a peice of shit poem that was from genuine ideas, i would rather mistakes of your own choice than a mistake of another's...

You have some potential for unique viewpoint, think about what you want to write, you should only write about what you thought about a lot, this seemed insincere, it didn't have yourself in it, eveb if you felt it so...

Improve idea's and complex structure, although trivial, does help to seem more proffesional, pull out your potential and don't hold back...