Someone help me figure this out. PLEASE!?

Look I cut. I know that's not a smart thing to do. I have been hurting myself since 7th grade and I'm in 8th now.
I know I started because I hated myself! I though I was fat, ugly, and ect. I even cry ed I though I looked so bad. I felt numb because of this sometimes, so I would scratch my arms till they went numb.
Then my Grandma -who takes care of me- finds out, takes me to a doctor because she figures it's my ADD meds that made me do it! She didn't listen when I tryed to tell her!
Then after a while I stopped, for like months, and then I think I got into a fight with my sister -who I love more than anything- and started to bite myself! So I went from scraching to biting!
Then biteing wasn't enouggh anymore! I started cutting! I would normaly just scarch with like a knife ,but it would be hard so it broke threw the skin.
But just today I used like a razer and all!

I don't even know why I do this! Help me out here! I mean at first it was out of self hate, but now…I don't know. I just feel like I need it!
I once though I maybe I did it just for the pain! But then I though maybe I got hooked on it or something.
Please help me!