I started PT for tennis elbow/elbow tendonitis in May. It is a condition that heals very slowly indeed. I have flare ups all the time and probably will now for quite some time. It occurred in my right elbow, even though my right arm has always been stronger than my left! The key to treating this is to strengthen the forearms as much as you can. In addition, you need to make sure you don't have an imbalance between the strength of the triceps muscle group and the biceps group. My biceps outclassed my triceps by miles, and I have found, consistently, that I can only now do bicep work and avoid significant elbow pain by doing triceps exercises first and often, with weights and bands: overhead presses, triceps pull downs and behind the body with bands. To strengthen forearms you need a variety of tools and exercises that include both wrist curls, palm up and palm down, but also wrist torquing actions (like when you wring out a wet cloth). In addition to the exercises my PT gave me, I found a whole load on youtube which are effective. I suggest browsing there. I was not advised by my PT to use compression or elbow compression. I read about this on several websites for bodybuilders where it was contraindicated. Everyone should do their own research though and find what works on an individual case basis. If I do my exercises assiduously, it keeps the pain at bay and allows me to do bicep work. Although my right forearm is now way stronger than the left, I will still get flare ups occasionally is I neglect tricep exercises or with heavy garden work with major cutting tools, as I have been doing for a week now, with a garden badly overgrown and in need of pruning savagely everywhere! Good luck!
Clare