Dislocations of shoulder

I am currently 43, when I was 17 I dislocated left shoulder in a bike wreck.
The ball part of the shoulder joint was clearly visible on my back.
I was put under during the repair job. No surgery no PT as I remember when I woke up I was fine other than some limited movement.
I did not stay immobilized at all simply went on with life with little problem. For the most part regained all use of the shoulder other than as I got older it would ache at night.4 days ago while water skiing I dislocated the same shoulder, it was extremely painful ends up the ball part of the joint was down and under my arm pit. Almost 3 hours passed before they put me under and repositioned the joint.
The doc sent me home in a sling but it is very painful to leave the arm in a same position for long periods.
I am almost pain free if I leave the arm out of the sling letting it hang while walking and propping it up while driving or working at the deck. Once propped up on the deck I can type 2 handed as well as ever.Am I screwing up moving my around? At night after about 3 hours of sleep I wake in pain and have to get up and move my shoulder around a while, the pain subsides and I can get another 2 to 3 hours before repeating the procedure.