Chest strain/ issue

Long time no see guys haha (my back issues are doing a lot better than they were before by the way not 100% bud way better than before). A few months ago I started having pain where my armpit tendon connects to my chest snd shoulder. I didn’t think anything of it at first thought it would go a way in a few weeks but it’s been 3 months now and still feels the same. When I massage the tendon on my armpit on the injured side it feels squishy and on the non injured side the tendon feels like it’s stiffer and stronger (what could that mean?). Also if I were to cross my arm over to the other side of my body like I’m doing a chest fly it starts to cramp up bad. I tried to do like super light tempo bench for a while and other variations but that wasn’t helping so now I’m just training surrounding muscles as best as u can.