I'm guessing that the OP did not realize they needed insurance the minute the paperwork was done. I am also guessing due to not realizing the necessity, no insurance was on the RV.
Sorry, toknow, this will be out of your pocket and you can sue the driver that did the damage.
My suggestion is to dig deep, find the money, do the repairs, and go camping. Why own an RV and not use it because you are squabbling over responsibility?