Fell off horse a few days ago and hit the ground hard on my left side.sharp pain in my upper back b/w my scapula and spine when i breathe/sneeze etc..?

Rib pain: You've most likely injured your rib cage and have inflammation of the ribs and pain. I suggest you see a doctor to make sure you've not injured any internal organs or your spine. For rib pain (costochondritis) rest, icing the area first and then applying heat, as well as anti-inflammatories like naproxyn (aleve) or ibuptofen (advil) help reduce the pain and inflammation.

Spine fall off horse: You could have a rib fracture causing this pain with breathing. You should also see a physician and obtain x-rays of your cervical and thoracic spine to rule out any fracture.