Pain in my shoulder. My workout again?

I have a pain in my shoulder for 6 months. I feel the pain when I lift my hand and stretch back my right shoulder . I go to gym and do weight training. I consulted ortho 3 months back for this and took xray and no issue found so doctor advised to take rest and tablets along with pain cream for 2 weeks. But the pain didn't go so the doctor told me it could be muscle tear / damage or some ligament problem and advised me to take mri scan to find it out. I stopped going to gym for last 3 months but I still feel the pain. This pain is not affecting my daily routine but unable to continue exercise because of this. What is the reason for this pain? Is it muscle tear? How can I get rid of this pain and start my workout again? Please help me.