I feel for ya. I went through 18 months of GE.
It could be your frame. But, honestly, it could be anything. As one poster above implied, GE has any number of causes.
You could start by switching back to your old frame and see if you improve. If that doesn't work, consider examining what you're doing on court. As a 5.0, its unlikely you have a glaring technique flaw. But since you instruct, you could be doing something that's just slightly off in terms of mechanics and doing it over and over again.
Keep in mind, tendonitis is an over-use injury—meaning you're putting undue stress on that tendon either by using it too much or using it in the wrong way.
Just try to be methodical in your search for relief. Consider your frame, your strings, your swing habits, your recovery periods, and so on.
And the very best of luck to you. I know what a trial GE can be.