First of all, I feel a bit sad for you, I think you are suffering a lot.
For fibrillation, there is a man who is in his sixties and walks every day for at least one hour. He said that in this way he controlled his problem of fibrillation. Unlike you, he suffers from high blood pressure, and he takes common "official" medicines, but the fact that he takes long walks every day is of enormous help to him. When it is too cold, he has a stepper, so he listens to music or watch TV while doing exercise.
The pain of his chest has frightened him for a lot of time, until he went to an old doctor that manipulated him on his back, and the pain disappeared.
I hope you will find a way to be well