I broke my elbow a number of years ago too, however not as bad as yours is, by the looks of the x-ray. I have 2 screws holding my elbow in place. I followed my therapy and pushed for range of motion. My Dr. told me to start moving my elbow 1 week after surgery. I now have 95% range of motion. If it doesn't hurt when you straighten you elbow, you are not pushing it far enough to extend the range. My Dr. said they shoot for regaining 60% to 80% range back.

Good luck