ScarletPimpernel, I'm not in a similar situation but just wanted to send some good thoughts and support your way!

One possible reason your fiance is sabotaging therapy is that he wants to keep you "under control." As long as you're "ill" and "unstable", you depend on him. If you change, it means something changes for him as well. But of course that's just one way of explaining/looking at it.

Stick to what you're doing and continue to work on becoming stronger!