Speaking from experience,
SH is an addictive behavior. There's the science side of it - where the brain releases chemicals that put the person in a state that is almost like a natural "high." And just the emotional addiction of the pain seeming more real because it's visible.
As a long-time cutter, I know how hard it is. It sounds like your to the point where your
SH is pretty serious and might be life-threatening. While I know that
SH is not a suicide attempt (been there, done that), it can still be a fatal action.
Do you trust a teacher, counselor, parent, or other adult enough to go to them with your concerns? They want only the best for you and sometimes are the direct gateway to professional help that can provide you with the resources you need to start to heal.
Two months is a huge step! I know you can do it again! I'm totally behind you. 110%!