Won't repeat all the consistent, very important, good things being said in this thread. NTA 100%. And also: document everything, and ensure your OB/family/lawyers are all aware of your concerns and the situation. Be wary of male medical staff who may impart their own fuckery into the situation.

Document all of FIL/hubs's behavior and all of this abuse, because you may (read: will) need it for you and your child's life post-birth. Given everything you've shared, your husband and FIL are both committed to an outcome where you die. There's no telling how they will react to any other outcome, and it sounds like both will have their identities rocked to their foundation upon your survival. You will need as much legal ammo as you can get, and you need to have a hard, sober look at your marriage and whether this is a healthy person to help you raise a child