I have a shoulder injury too, I dislocated my shoulder twice due to bad exercising.
I think your situation is like me. Your shoulder got dislocated and got into place again. The same happend to me, I think you need to your a dr and he might ask you for an MRI and you might need a surgery to fix it.
Anyway, I will not have this surgery. It's very expenisve and I don't have health insurance. Instead I'm being very careful about how to move and workout, I do use dumbbells but I'm being very careful about it. My shoulder is getting stronger, the muscles, but the problem is the ligaments. The surgery fixes the ligaments.