I have Shimano brakes, and I have them double shimmed (two sets of shims per brake lever). I have really tiny hands. It really helps.

Also, if you are on a hybrid, does that mean you have flat-bar handle bars? When I first started biking, I had a mountain bike that was never properly fitted to me. I ended up with loads of pain in my wrists and elbows.

Later, I got a road bike (Specialized), and the bars have a wonderful, curvy shape...even more curvy than a lot of other road bikes I've seen. Those bars, including the bar phat gel underneath the tape, have eliminated my elbow and wrist pains. I know you have a pre-existing condition, as you mentioned, but maybe more options on your handlebars would help?