What Causes Burning Sensation On Sides, Sore Underarms And Chest Pain?

My skin feels sunburned on the left side of my back and left side of my chest but there is nothing there. My underarm is very sore to the touch. I have had some chest pain and difficulty breathing, but its very moderate. I also haven't had regular bowel movements. This has gone on for over a week. I am stressed and attributed the chest pain to stress or a panic attack but its been over a week and now Im wondering if it is more than that.