In about February this year I started getting really bad RSI (Repetitive Strain Injury) from using of all things a Wacom.
It seemed to come out of nowhere and got to the point where I couldn't draw at all without significant pain in my elbow/wrist and shoulder.
My hand was in a splint for about 6 weeks and I couldn't use my wrist. I was diagnosed with De Quervain's tenosynovitis. Its been 6 months now and I have been to a hand therapist but doing illustrations was still very painful.
In July this year I started seeing a Occupational Therapist recommended by a friend. I was very sceptical as I am sceptical about anything but doctors in general. Basically he was telling me to 'move more' and gave me a lot of exercises to make my hand much stronger. He also told me my brain is re in-forcing the fact that my wrist is painful which is something I have read about with chronic pain.
Around the same time I invested in a large screen (I used to just work on a small mac) - 2 extra types of mouse (in addition to the Wacom), and a different chair. I am sitting straighter and doing hand exercises.
I wouldn't say Im 100% better but definitely 70-80%. Also one of the other things causing my De Quervain's was using my thumb on my iPhone, so I use my left hand with my phone now and try to limit my phone use (which is incredibly hard and I cant say I have achieved that goal). I was also recommended This book 'Draw Stronger' from Kriota Willberg. Most of the exercises in there were the same as the ones the Occupational Therapist gave me.
I think my recovery was a combination of things.. but if you have similar pain hopefully some of these ideas can help.
I went to Biomechanics Healthcare in Cronulla.