Sorry to hear you are feeling high stress levels from dealing with BP and caregiving to someone that you have always had difficulty being around.

It sounds like your financial situation prevents moving out and trying to bring a new girlfriend into that kind of situation would challenge and possibly destroy any relationship

Is there any possible way of making a separate apartment out of the house for yourself with your own entrance? Or if there was a cottage out back that you could get away from it all when the mild weather comes back.

Does he have any other relatives that would spell you?

Is he financially able to pay you a certain amount of money for caregiving services? Having money would allow you time away.

Can he afford a private attendant a couple weekends a month so you can get away?

A therapist or social worker might help you work through anger and resentment and also provide possible solutions.