Welcome. Sorry you are here.
I’ll defer to others to address your main questions. In the meantime, this might help you with the hypertonic tendons and muscles.
I think one of the best references available is the Trigger Point Therapy workbook, see
this link.
We’ve also talked about the Theracane as a good tool for self-treatment. It’s also on Amazon at
this link. I still use this on occasion -- it's awesome and simple to use.
Here’s a good overview of “contemporary” thought on the cause & treatment of trigger points:
Trigger Points: Diagnosis and Management - American Family Physician