So I finally have some answers to my pain issues and some guidance on how to hopefully recover. Only took 5 different practitioners and a whole lotta $$ in testing.

In the end, it was a referral to an amazing sports med practice that finally got me somewhere - I can’t express the relief I felt with professionals that don’t want to mask the problem, but want to solve it and get me back to running pain-free!
X-rays show major compression in my lower spine; getting an MRI Thursday to get more detail on that. But doctor feels that compression is pinching multiple nerves, including sciatic, and has caused muscle weakness, which, in turn, has forced other muscles to get overworked to compensate. My chronic pain is a combination of nerve pain and the overworked muscles. I just started PT and the physical therapist is a runner, which is great, and absolutely feels this is fixable, which is REALLY great!
I’m still doing 3-5 mile run/walks, but with more walking and less running than my usual… which is honestly delightful in the heat of FL summer and probably what I should be doing EVERY summer just to deal with the heat. This is the least amount of weekly/monthly mileage I’ve done in many years, which feels odd… but it’s actually pretty nice to have more free time and not constantly feel worn out from cumulative heat stress! Highly recommend.