Little Lyon - your LBS should be able to do a proper fit, and the folks working there probably know medical professionals - Orthopedic surgeons, PT, massage therapists that they've had good care from, and are used to working with cyclists/athletes. So while you're getting a proper fit, it will take time, wear your biking kit, ask them about who they've seen. Tell them your PT wants you to give up your bike, but you don't want to.

Good luck! And you can recover from the should impingement and ride again (I did).