Maybe you have already tried this, but if you can get a hold of an iPad and the app Procreate, please try it out. You can customize your different brushes in ways that I think might help with your particular mobility issues (e.g. add more stabilization, remove or alter the pressure sensitivity). You can also do things like draw a curve but hold your pen down, and then it smooths and turns into a shape you can resize or change the arc of. Same with lines (wiggly become straight).

The artist wound is so real. ❤️