I used to draw on myself where ever I felt the urge to cut,
I started with sharp-point red pens, and then I'd go to ballpoint pens, to washable markers, I'd draw swirls or lines, or words, or anything, just to get it out. I also used to go for walks in the middle of the night, just to clear my head..
It helped a lot and ultimately I no longer feel that urge.
Good luck to you all, much respect to you.