My Shoulder Has Been In Pain, Every Time I Move

My shoulder has been in pain, every time I move it, it makes a popping noise. I’m a Boxer & I recently went to 2 Doctor’s which they’ve done an MRI and an X-ray but found nothing. I’m going to therapy because that’s what they requested but it’s feels like therapy is just making the pain worst. I just need another opinion to what can this be ?