It is certainly not impossible to quit or be controlled, but I understand how it feels that way to you now. Have a look at this thread, what thoughts you have written about yourself. There is a self loathing there, do you feel like you dont deserve to be happy? Why? When you address some of these issues then the urges to cut wont come so often, the triggers wont set you off as much and you will be able to help yourself recover. There is hope, and many many people who have been through this.