Have you identified the cause? I had it, but not as badly as you, and it came from typing and mostly mousing too much. It was in my right arm (I'm right handed). I had PT for about six months and had to cut way down on my typing, which was hard because I'm a grant writer so I had to type and mouse.
I considered getting voice recognition software, but the PT and rest helped. The biggest help, however, was switching the mouse to my left hand, and taking frequent breaks from typing. And continuing with my PT exercises even after I stopped going to the PT.
It seems like if you can figure out the cause, you can the action that is causing the the irritation and inflammation, and maybe you can avoid surgery.