18 years old, debilitating back pain, possible trauma? Who should I see?

I'm an 18 year old college student. I was driving my boyfriend's scooter and I crashed (I know, I'm a total klutz) and skidded across the road. Aside from a few bruises, I felt fine. A few days later, my back began to hurt - laying down straight on my back was especially painful. But it was getting better, and nothing I couldn't deal with. However, today I jumped off my bed to get a pen that had fallen on the floor and experienced excruciating pain in the lower left side of my back (I fell on my left side). It is extremely, extremely painful and now it won't go away, no matter how I lay down. Should I go see a doctor, or a chiropractor, or what? Or should I wait and see? I won't be able to attend class in pain like this - I can barely move. :(