How to deal with an accident caused by brake checking?

I have recently experienced a car accident. I was driving casually merging into another freeway from an off-ramp. There was a black Lexus SC430 coupe tailgating me but I just ignored it and started merging into the other lanes. Apparently he was trying to p me up from the left and kept merging out. At this point, I merged 2 lanes and was making my move to merge into Lane 2(lane next to the fast lane) but I noticed he beat me to it and ped me up. I gave him a gesture of "okay go ahead" and apparently he didn't take a liking to it. When I merged into Lane 2(I was behind him at this point) he brake checked me. I braked suddenly and spun out of control. First, I rammed into a big rig in the slow lane then swerved back into the center divider and rammed directly into that. Thankfully I didn't involve anybody else(other than the big rig driver) in the accident and people behind me witnessed the entire altercation. Unfortunately I was unable to get the license plate of the car because he sped away but I got a glimpse of his face and know the model of his car. I was wondering how I should deal with this situation. I'm 22 and still in college now without a car. This is a frustrating experience to say the least.