usually insurance will contact with you, tell you what kinds of things you have to do.
But you have to make sure how much insurance coverage, generally will be $50,000 for total, some less maybe $25,000,including hospital fee and car damages.Looks like your case is over this amount.
I suggest you just contact both insurance company, if they do not contact with you.
If you are not satisfied with insurance redeem in 3 years since that bad day, you have right to go to lawsuit.
thanks god, your LD(I don't know what is mean) is OK.