I am experiencing an excruciating pain in my right lower back, it hurts when i move or breath. i had gym class today and played a sport maybe thats it?

Myalgia: time to get examined. It sounds like a pulled or strained back muscle which should be examined, evaluated, diagnosed and treated.

Suggest: Although you may be merely experiencing musculo-ligamentous strain/ sprain, there are other causes of back pain which could be considered (even a kidney stone), so, see your doctor and stop trying to figure it out yourself.