I just coughed and it feels like a have a charlie horse in my back. I can't move at all and when I eat the pain worsens its on my left upper side?

Splinting cough pain. Your coughing might have caused a stitch in your back due to strain of the muscles between the ribs as well as in the back, or even a shift of ribs/neck/vertebrae. Lungs and other internal organs can send referred pain signals to your musculoskeletal system (viscerosomatic reflexes is the term). See your primary care provider to confirm it's not pneumonia etc; then see a do/md/pt to get moving.
See your doctor. You should see your doctor-the 'charlie horse' could be a sign of pneumonia or costochondritis. If you have any shortness of breath-go immediately.