I think you need to be working with a therapist who understands much better how to work with SH. You need to be Given control over your behavior, not have that control taken by others. Try some online search for counselors in the area who use DBT, CBT, or other therapeutic models that address learning ways to change/modify your own thoughts and actions. It is just an opinion, but I do have a good background in working with SH, and the worst outcomes I have seen are connected to over-control, too much time in the hospital, and the emphasis of shame in forcing you to display your wounds to others. You can do an online search, or even contact the local MH center to ask about folks who specialize in this, and what resources they have that you might be able to use.
Maybe someone here can recommend some good reading too---my brain is not quite awake. Hang in there.