Yes, you can stop yourself. I think the problem is you don't want to. Your hands don't move on their own; you keep choosing to touch her. You need to accept that doing so is not ok, choose to stop, and then stop. Telling yourself that you can't is only perpetuating the problem.

People don't say "oh, I agreed that I wouldn't murder a friend, but I just can't stop myself from stabbing her." How is this situation any different, at all.