I'm a doctor but i cannot help you here because you need to be examined in person sorry. But you might have strained or damaged one of your rotator cuff muscles. I suggest you see the orthopaedics department asap and don't aggravate it further by trying to train through the pain.

Did younundergo any surgery? How bad was it?

I hope you went for physiotherapy. A few months isn't going to be enough to ensure optimal limb strength. Check with a doc please.