We used to think that tennis elbow was due to inflammation alone.

As you say, now many doctors these days think that it is from overuse and injury of the tendon fibers and the treatment is stop doing what injured it. At least try to do it a little differently, i.e. different grip, new racket, “tennis elbow” brace, exercise surrounding muscles.

Sometimes you just have to give it up and rest it for a few weeks.