You know, some people sometimes have to deal with more than they should, especially when they are a young child. Sometimes we're forced to grow up earlier than we are ready, and simply put, many of the things that happen as a child cut deep, and they may never go away. But I have one thing to say to you... I may not be able to make it go away, but you've made it this far. Do you realize how much strength that shows you have? And that being said, you're still going. Respect that in yourself, that's something you should be proud of, and you should never give up on.
The best you can do is live with what you're given, and instead of letting these things kick you down, let them give you experience and knowledge. Let them make YOU the better person, and let them show your strength and prove it to yourself.
Your life is something that you control, but sometomes our emotions take the better of us. It's natural, and sometimes you just need someone to turn to. You are very lucky to have some friends that are really supportive of you. Sometimes friends come and go, but there are some friends that will stick by you forever, and even if they don't say anything, you'll always know that they're there.
You're still hanging in there, right? So much has happened, and yet you're still here... Why is that? Is it because you have great, supportive friends? Is it because you have the strength to keep going? Is it because you're determined to make something of yourself and create a happy life? Is it all of those things? Whatever it is, keep using it. Hurting yourself... the one thing I learned about hurting myself, mentally and physically... was that it hurt the people that cared about me more.
When I was in a depressive state, I hated myself more than anyone. I could cut myself and tell myself I deserved it... and I could tell myself horrible things about me, and believe it to be true. But I suppose one friend of mine truly made me realize that these things can actually hurt OTHERS more than myself. Your friends just want to see you happy, and that's why they are trying their best to help you cope with your emotions :).
I wish I could help you, it all falls on your shoulders. You may not have much of a choice as to where your life is going NOW, but with time, you'll be in control. You can chose how you want to live your life, and live without the fear of being judged and hurt by those around you. Give it time, stick with it, and maybe then you will find your reason to stop hurting yourself ;).