Oh wow, you have definitely been through so much, losing all family members is really devastating. I lost one and it was quite painful. I do pray that of all doctors you have seen, one will find a way of properly managing and improving your condition. As long as you are alive things can change for the better. Don't forget the spiritual side too, there's a higher power you can rely on.
Thank you for finding the courage to share what you are going through and am wishing you the very best :}