Shoulder pain

One day, I suddenly started experiencing shoulder pain. When I lower my arm, there is little pain, but when I try to lift it or move it backward, I experience pain that makes the movement unnatural. If I try to press both arms against the wall and touch the back of my hands to the wall, I can do it with one arm, but the other arm is so painful that I cannot touch the back of my hand to the wall. When I try to lift my arms with my hands touching my ears, it hurts and I cannot fully extend them, but after repeatedly doing it, I can lift them a bit, although the movement is still not smooth or natural. Some people say it might be due to calcification, but is it correct that these symptoms are caused by calcification? If it is calcification, how is it treated and can it be fully recovered?