Popping or clicking sound in left should

It's been 6-7 years since this problem started. In college days, I used to go to gym, wasn't aware of any proper form or technique, whatever knowledge we had was "Bro Science" someday I might have gone lil beyond my limits, suddenly it started hurting, i asked trainer he said it's okay it happens, remember no pain no gain, keep doing your workout, and i kept on doing it. But pain got severe so had to home. Pain got reduced started working out again next day onwards but now whenever I lift lil heavy it starts paining, but i didn't stopped working out for the Next 3-5 years but i always tried to avoid shoulder workout because it always gives pain. It's been 7 years problem is still the same whenever i lift my hand i can easily ALWAYS hear that heavy clicking sound even while doing every day work. Generally​ it's Okay. But when i try workout, lift heavy it gives immense pain. I don't whether it can be healed or not or how much time it gonna take. Thanks in advance