Jan, I've been experiencing strange muscle and nerve pain in recent times. That's why I asked about your spine. Mine started out just one arm, then that started feeling a little better... then it changed sides and all sorts of weird things have been going on... I have got to the stage after an episode yesterday where I think all my pain is coming from a problem in my c-spine. It's been some years since I had that checked and didn't really feel like doing all that again.
I also did a lot of heavy lifting years ago as a nurse, and in more recent times as a stay at home mum who insisted on doing all the landscaping myself. Not anymore!
I hope the doctor is treating your Strep. throat. That's certainly something I'd be keeping an eye on if you already have mitral valve prolapse. [You didn't have rheumatic fever as a child did you? Just curious.]
Well, hopefully someone else might have some more suggestions for you.

Just be careful, Jan. It's difficult sometimes with so many different symptoms... they can be caused by such varied problems.