First of all, your mother loves you and wants you around for a long time. No one but a mother knows that feeling. Believe me, I am a pro at it.
But, what you have got to realize is that she is seeming overly spy crazy because she does love you.
Now, let's get to the issues at hand. You must learn how to release that anger or hate in other ways then cutting. If it is a person that is triggering this, then you have to go to this person and tell them how thier action are affecting your life and you can choose to be friends or not. Personally, if they are causing you this much greaf, I say get rid of them. Peer pressure is another thing. You are your own person. You DON'T have to do something because the rest of the gang does it and you feel you will be a laughing stock. Find other way to let out you anger. Go outside and yell in the a solitude area or something. Cutting is a very serious thing and can lead to much more as you know have thoughts of suicide. And by doing so, who are you hurting. The ones that love you and are left behind to greave. Is that what you want, to teach them all a lesson? That does not work. You will be gone and everyone other then your family will forget you ever exsisted.
Now, for depression. I think if you would seek help for this, it may very well help with you cutting also. You have got to get some help and soon. Just remember as the other posters have said. Your mother loves you. And enough to want you to be around for a very long time. Do you love your mother? Then why would you hurt her so.
Carrie