Good to hear you are trying to get off the percocet. If the OTC stuff works, you should be able to think clearer and not feel so loopy (OTOH, you may like that spaced-out feeling
), especially if you are going to try to drive.
Hoping the best for you on that first therapy session. The number of weeks (months) you spend in structured therapy will depend on your efforts and desire to regain flexibility in that shoulder joint. It's the beginning of a long journey.
You are Airborne....I believe you'll do well!