A physiotherapist might be able to work with you on some stretches or exercises to relieve pain and strengthen your muscles so they don't wear out. If it's documented by your doctor, you might get better coverage under medicare /insurance / worker's comp / etc. The advantage of going through a physiotherapist is that they'll be able to tell you if you're doing something wrong that will worsen your outcome.

I do a few stretches that seem to help me when I flare up. The most effective is when you place your hands palm together in front of your chest like you're praying 🙏 and then slowly rotate them so that your fingers point towards the ground. I can definitely feel the tension, and if it hurts like a bastard then don't do it. But stretching for a few minutes a few times each day makes a big difference personally.

To add to bougie birdie's reply, a doctor would be able to actually diagnose you and determine if this is a nerve related issue, repetitive stress injury, or potentially early signs of a degenerative disorder such as arthritis, etc. The treatment for a repetitive stress injury, if that is what is causing your pain, could include things like specialized brace to immobilize certain parts of your hand so they can heal properly (especially important during sleep).

My partner had a repetitive stress injury that she had diagnosed and then didn't see a therapist for (at first). Her injury did not heal even though she was not using that part of her hand until she finally went to an occupational therapist and got an appropriate brace (and instructions for tendon gliding exercises).

Have you tried a trackball?