Say it with me, folks: the doctors shrugged their shoulders, and said "hellifweknow." It doesn't matter whether it's mental confusion, shortness of breath, what have you. They can't find anything. They can't find a single damn thing. Yay, medical science.
Damn, that sucks. :( I hope someone has a flash of inspiration.

Sending many hugs. And keep counting the wins. You are doing very well, for facing such big upheaval.