If you haven't already, take pictures. Lots of pictures, of everything you can think of, relative to the damage to your truck and trailer.
Get a copy of the police report. Make sure you have the investigating officer(s) name(s) and badge numbers. Make sure you have the name of the officer's supervisor who signed off on his/her report.
Find out if the state in which this happened is a no-fault state or a tort state. It can make a difference as to the degree of responsibility. Even though the officer said it was 100% the other driver's fault, if he hires an attorney, he could try to blindside you. Make sure that the police report says that it was 100% the other driver's fault. Consult your own attorney (as mentioned previously) to know your rights in that state. It may differ from your home state (if this did not occur in your home state).
Do not sign anything until you consult an attorney. Do not waive any of your rights. You don't have to tell anyone you're consulting an attorney, but do so...immediately. Your future could depend on it.