There is a new survey out about the happiest professions. I think the whole premise is flawed. You're supposed to find true happiness outside of work. From friends, family, and YouTube videos of old people falling down.
I burned out my drawing hand by using it too much. The common word for it is writer's cramp. The fancy words for it are focal dystonia. The symptom in my case was a pinky finger that went spastic when I tried to draw.