I had similar issues three years ago. I immediately switched from the QWERTY key mapping to Dvorak and swapped Left-Control with Caps Lock. (For fellow Linux users, that means running "setxkbmap dvorak option ctrl:swapcaps" every time your system boots up.)
I also went back to using my (dominant) right hand instead of my left to move the mouse. (I thought being able to do things with both hands was cool but my left hand was so relatively weak compared to my right that I was holding the mouse incorrectly, resulting in severe wrist pain).
The third thing I did was take vitamin B-12 supplements based upon something I read online, but I'm not sure this had much to do with it.
As a result, the pain was gone in no time and I am still pain-free to this day.
I also went back to using my (dominant) right hand instead of my left to move the mouse. (I thought being able to do things with both hands was cool but my left hand was so relatively weak compared to my right that I was holding the mouse incorrectly, resulting in severe wrist pain).
The third thing I did was take vitamin B-12 supplements based upon something I read online, but I'm not sure this had much to do with it.
As a result, the pain was gone in no time and I am still pain-free to this day.