Try moving the mouse to the left of the computer, and use your left middle finger as the primary button pusher, and the left pointer finger as the secondary button pusher. You dont have to change button values or anything.

I had a 30 year career in computers. I had to start left-mousing idk after 20 years maybe due to pain and weakness. Another advantage is it frees up your right hand to enter numbers quickly if your keyboard has a number pad.