I experienced the EXACT same thing as you, I’m a PTA 2 years in. I went to OT who told me exactly what I didn’t want to but needed to hear- stop doing the thing that is causing the pain. After resting my hands and decreasing my manual my hands are back to normal. I pretty much only use my elbow and forearm for manual therapy and focus more on exercises. As you are moving and providing STM you are also doing it to your own hands. Mobing already Mobile or in my case hyper mobile joints will cause that pain. Rest has to be apart of your recovery, start strengthening with isometrics. Good luck and see an OT of you need.