Sounds like and looks like Golfer's Elbow / Medial Epicondylitis / Pitchers Elbow (which is a form of tendonitis).
I definitely recommend putting a cold compress on it, if you haven't already, and especially after you are active with it. You want to get down as much inflammation as possible. If the inflammation is always present, it forms a barrier and blocks the bodies natural ability to bring blood flow to the area. I have included a link for more info on Golfer's Elbow and a really good treatment i recommend. All the best.
Golfer's Elbow Treatment