I relapsed again...

I have, what I suppose you could call an “addiction” or a “fixation” to cutting myself... two days ago, for what had got to be the hundredth time after trying to quit, I relapsed again. I cut my wrist, deeper than I ever have, but not enough for stitching. It’s not suicide attempt, it’s just an addiction to pain by cutting.... I finally told my SO of 5.5 years, and at this point he just seems to have given up on trying to help me.... we haven’t sought professional crisis help because we’re afraid it will ruin our plans for the future.. I’m afraid he’ll give up on me for good.... I don’t know if I can give up cutting.. please, if anyone has any advice out there, I need to know what to do....