I think first, we health anxious people tend to beat ourselves up for past decisions. It's not helpful. It's a version of perfectionism I think. Try to let that go.

Seeking advice of a physio first an excellent idea. They are the real experts on this stuff. You don't mention your age but you would be hard pressed to find someone much over 40 that hasn't had back or other musco-skeletal issues and you clearly have a taxing job. The physio can look at all of that for you.

I think these things can always be improved. The body is a kinetic chain so if one bit is out other bits can hurt.

You are doing all you can now by seeing physio. Let us know how you get on. You will be ok. Wheelchair territory is just your anxious mind catastrophizing.