Glad you're not seriously damaged, but see a good MD about your back. Most problems and pain will not surface for days or even weeks, by then the damage is done... see a doctor now and insist on an MRI, X-rays won't show most back injuries.
Hope they catch the guy that did this and make him pay! It's bad enough he hit you, but very stupid to leave the scene.
Get better real soon and keep us up to date on the situation.
Good Luck and God Bless,
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles