How To Treat A Back Injury?

I am 66 yrs old. I fell last week off a step stool. I fell about 4 feet. I hit on my back. I was on meds. I did not miss the step. It was like I thought I was on the floor. I just stepped backwards. I have put ice here and there on my tail none area. The pain increases on a daily basis. What I have Google it appears it is my tailbone. Im on Narco already for other problems. I bought a pillow yestersday. It is oval with the center cut out. I can't hardly stand sitting on it. No pain standing, or driving. Can't stand sitting or bending forward while sitting down. Help!