Why am I having chest wall pain? Makes it tough to keep working into the night.

Usually is. Chest wall pain is generally due to a strained muscle, contused or broken rib, or arthritis/rheumatism of the costo-chondral joints (the attachment of rib to cartilage). Heat, physical therapy, acupuncture and pain relieving drugs are the usual course of therapy. Many forms are self-limited and if persistent, further evaluation is indicated.