Sounds more like a tendon/ligament problem rather than the actual deltoid, unless you have swelling of the delt. My shoulder has been an issue over the past few years. The work capacity is slowly eroding. I suggest a doctor or orthopedic specialist. You could google diagnostic manipulation techniques to try to get an idea of what's wrong before you go. The shoulder is just so complex that it really takes an expert to find the root cause. In the meantime plenty of rest, proper stretching, foam rolling, and ice/heat therapy. Look up rotator strengthening techniques. I don't advise Any anti-inflammatories as it can mask the pain leading to greater injury. DAA will do nothing towards healing. Fish/flax oils, multivitamin, extra vitamin c and calcium are all great for overall joint health. 215to 45 is a huge drop. Something could be very wrong. Oh, and stop military pressing till you get it sorted out.