Hot Fomentation. Gentle Shoulder Stretching. Core Strengthening Exercises. Gentle Neck Exercises. Avoid sleeping on affected side.. Warm up and cool down is a must.

Dear Sir Shoulder pain can be due to several conditions. A detailed clinical examination by a shoulder specialist is recommended.

It is possible that you may have injured your shoulder in that incident and now are suffering instability.  However further comments can only be made after evaluating the shoulder joint and checking of the ligaments and muscles around the joint. Clinical Evaluation and mri findings will indicate the severity of the injury.  Most of the times such an injury does get sorted with a good 6 week rehab before high intensity gymming again.