My experience:- was with tendonitis in my forearm was in my left arm and was from signing the kite too much in light winds. I thought that I would have to suffer with it for ages as this was 'everyone elses' experience etc.
I went and saw my Osteopath for a couple of sessions who helped relax the muscles in my shoulder and the tendons down the length of my arms...I also had a rubber ball / tennis ball that I used to rub across my bicep and down the elbow joint and across the forearm, also use to put it on the desk or kitchen table and roll the palm of my hand across it. You will find 'hot spots' these got extra attention.
My remedial masseur also did some trigger point therapy down my left arm...it was intense, it hurt but it went away in about 6 - 8 weeks. During this time, I did use a strap across my forearm when kiting and didn't 'over do it'.
Everyone heals differently and different things work for different people.
Good luck - wishing you a speedy recovery