Hello,
Have you considered any expert chiropractic care?
If foundation is "crooked" better to fix it first then move forward..for best results..
I'm thinking the arm yanking incident might be something that chiro might be able to do something about, perhaps something got out from that.
My chiro adjusted wrist, arms, shoulder, hips, even my ankle & foot. But when you have something like TOS find the best most experienced one you can..
Mine also used PT modalities - ultrasound, Low level laser, IF stim, manual trigger point work and some deep tissue.. it was very helpful.

I definitely would stop the weights if you haven't yet. I can't believe that didn't even suggest that..

Have you found the useful sticky threads at the top of the TOS forum thread list?
Post #1 has so much info it is a bit of a crash course on TOS.
You'll find site links with descriptions of the types of TOS and that will help you when talking with drs & PT persons.
All of our sticky threads have great info and you can explore them at your own pace.