Back in August I was experiencing the same issue you're describing. It has taken until now, four months to fully recover. It was a real scare for me. I stopped shooting completely for about six weeks, maybe more and it really showed in the early part of my deer season. I've since dropped bow weight from 55# down into the mid 40#'s and don't plan on going back up. No need to risk it.
I don't have the insurance or cash for MRI's and doctors, so I did a lot of self diagnosing research. All the symptoms point to a ligament strain, can't remember the proper name of witch one it was. Good luck, I can tell you it really stinks not being able to shoot. I shot injured longer than I should have. I'm sure that made recovery take longer. I finally just said I gotta stop and hope this get's better.