I battled with medial epicondylitis ("golfer's elbow", which often has nothing to do with golf) for more than 5 years, and I'm pleased/relieved to report that it's completely healed. I can offer a couple of things for your consideration.
1) Get a set of these:
Rogue Fitness - VooDoo Bands
2) Use the above bands to stretch like this:
Elbow Pain Medial and Lateral Epicondylitis BAM the fix! | Trevor Bachmeyer | SmashweRx - YouTube
3) Try a low carb diet. I've been on a ketogenic diet now for a couple of months, and it has done more to bring inflammation down than any single other thing I've done. My whole body feels restored, including a twice-rebuilt shoulder and a Tommy-John elbow, and chronic knee tendonitis.
My theory on why this condition becomes chronic is that the forearm muscles tighten up due to micro-injury (overuse), and the unrelenting tension perpetuates the problem, disallowing the tendon connection points a chance to heal. Proper stretching causes myofascial release, easing the tension on the injury, giving your body a chance to heal itself (WAY better option than surgery!).
I'm 40 years old, live a very active lifestyle, had tried everything (cortisone, PRP injections, dry needling [which did help some], therapy, prolonged rest [like pretending I didn't have arms], etc.). I was figuring I'd have to deal with tendonitis for the rest of my life, so it's with no small amount of satisfaction that I can say that I'm healed and able to continue doing the things I enjoy.
That's my experience with it, FWIW.