Hang in there! Find a specialist with knowledge of how the condition affects playing ability--get a second (or a third) opinion if you have to. And don't give up! It's a drag, I know--I injured my left-hand pinky a couple of years ago; took a dive in my hallway at home and crushed the finger between my cell phone in my shirt pocket and the wood floor, the finger bent and wouldn't straighten up under its own power. I went to the emergency room, got it X-rayed, and was told there was a loose chip of bone in there, probably from an old injury, and I should use the finger as much as possible. I didn't think so--I'd never injured that finger before--and the more I tried to use the finger, the worse it stuck. Playing was out of the question, as the finger would bend under the others and get in the way. I thought I was done as a guitar player. I went to see an orthopedist who's also a keyboard player--I used to play gigs with him--and he sent me for an MRI and found out that I'd torn the extensor tendon loose--it was actually attached to that tiny bone chip that was floating around loose in there. He put a splint on it and told me not to use the finger for at least six weeks. Fine with me, as I was scheduled for knee replacement surgery the following week anyway. After a month the splint came off for examination, and I'd actually healed up enough to bend and straighten the finger, although it was really stiff. I had to wear the splint for another two weeks, but when it came off for good I was able to work on getting some chops back. The doctor said he'd never seen an injury like that before, and if the splint hadn't worked, surgery would have been the only option--and that would have rendered the finger permanently unusable. I'd been seriously considering switching to bass, but I can play guitar again now, although my chops may never be what they were before. I've spent a lot of time thinking about Les Paul, Tony Iommi, and Django Reinhardt, who all suffered traumatic hand or arm injuries and went on to become great players in spite of it.
So don't take "No" for an answer, and get a good specialist and therapist on your team--and remember Dave Mustaine, who had the same condition and came out the other side.