Overuse injury?

Hi All!
This one may sound weird, but I'm going to give it a shot. I'm a teacher who paints houses during my "summers off". I am right handed and noticed pain in my elbow about halfway through the summer. I wrote it off as overuse and assumed that when school started again it would subside. It hasn't. It feels like the tricep, especially just above the elbow, is weak and sore. I plan on icing, stretching, etc. before going to a doctor. It's not debilitating, so I was hoping for some ideas before making a bigger deal out of it. By the way, I was a pitcher in high school and college, as a result I have a history of tendonitis. Any comments would be appreciated!
Thanks!