What should I do to help my sprained back heal?

Lots of things. Dont sit or stand in one place for long periods of time. It is good to take frequent short walks. Be careful lifting, bending, pushing and pulling things. If you have to lift keep your back straight and lift with bent knees. Sleep with your knees bent and a roll between your knees and underneath them. Ice back after use and apply moist heat imbetween. Otc meds can help. See dr if not improving.