You have a pneumothorax. This means that you have a partial collapse of one of your lungs.
This condition may occur spontaneously, or may develop from a chest injury. People with a spontaneous pneumothorax can have a problem with repeated episodes. A catheter (chest tube) may be inserted between your ribs. This slowly removes the air from around the lung over a few days. Hospital care will likely be needed if you have a chest tube. Hospital care may be needed if your condition worsens, if the lung does not expand fully, or if you have other significant injuries like fractured ribs.
Your condition does not appear to require hospital care at this time. Rest as much as possible and avoid any strenuous activity until the lung is normal and your doctor approves. Do not smoke or drink alcohol. Call your doctor or go to the emergency room at once if you develop increased chest pain, more shortness of breath, pain on both sides of the chest, or a fever.