Go to the ER and get checked out. X-rays and all that. I had a similar crash when I was 18, and it took 20 years for the side affects to start showing up. I found out 10 years later that I had broken 4 ribs and will have some nasty arthritis as a result. I also had to have knee sugery that was from tissue damage caused by the crash.
I know this sounds lame, but you might want to speak with a personal injury attorney too. I did not, and have had many missed work days due to back issues caused by the crash.