I had a similar thing after a summer of building pools and decks. I was using the same arm to mini-sledge spikes etc... Developed bursitis in that shoulder. Went numb constantly if I laid down on either side but when I would roll onyo the injured side forget it, a few times I slept so hard I didnt realize and the arm felt dead when I woke up, panicked a few times. Time and rest healed it. I would HIGHLY recommend a BPC157 regiment. Works wonders!!!