Share 'Rehabing a shoulder injury'

I have been dealing with a shoulder that starts hurting after 18 holes and wont allow forhand throws due to stabbing pains across the top of the shoulder ,I can normally throw 72 holes with no soreness so this bum shoulder is really ticking me off ,I know im getting older(42) has anyone else run into this type of shoulder problem and any advice (beside not throwing..lol) on rehabing a shoulder