While this could be anxiety, either all or in part, I would not make that assumption. The chest pain
sounds like what we call chest
that arises from the skin, ribs, cartilage, muscles or intercostal nerves, to be distinguished from that which arises from the internal structures, such as the lung, heart and pleura. That you can reproduce the pain by altering your body position also suggests that it may be musculoskeletal pain.