Hypermobility causing nerve pain in arms and hands

Hi. I’ve been having bilateral nerve pain that started in my thumbs for over 3 months now. It went up my radial nerve into my neck and hurts all along that. I’ve been in OT and PT for it and they’ve been thinking it’s thoracic outlet syndrome or c6 radiculopathy. The last few weeks I started having severe ulnar nerve pain in both arms in my elbow la and down my forearms to my pinkies that didn’t make sense to my OT and PT given the exercises I’ve been doing. I saw my rheumatologist today (I see her for my raynauds) and she says it’s all just because of my hypermobility so I should immobilize my elbows and fingers. Has anyone else experienced this? Does immobilizing help? Any cheap recommendations to start? Don’t really have the money to buy custom metal ring splints.

I also have knee pain that she said was unrelated and caused by bursitis in both knees. And I also get sciatic nerve pain behind my knees that is also thought to be related to my hypermobility.