Really sorry to read that. It must be so difficult for u.
I think u need to make ur husband see whats going on here. There is care and then there is control and u stated, ur FIL is controlling all aspects of ur life and if u dont take control soon, he will also control ur kids and their future.
It will take time but u need to start working on your husband, like one nite organise a romantic meal for him and a few days before pump him up by telling him what u have in store for him, so that he will look forward to it. That way he will be the one who will call inform his family that u wont be coming over that evening etc, u wont have to be involved in that, then make sure u have a brilliant meal and nite, somethin he wont forget. Trust me, most guys are the same hahah.
Carry on doing spontaneous things for him and he will eventually be putty in ur hands. then u can steer him away from the constant controlling and visits.
Hope it works for u…it worked for me. my inlaws were like that and i literally went and took control of my situation before having my baby and now i dont have to answer to anyone but my husband.
trust me, nothing works for this mama boy, daddy boy types. I say ignore ignore ignore. Ignore your husband as well, if he cant stand up for your rights than he doesnt deserve your love or patience.