BTW; you probably know this but see a doctor by the weekend to make sure you don't have whiplash (I have had this show up after a few days), do not sign any insurance paperwork until you have received your doctor's report etc. Insurance companies can be scum bags who try to settle quickly before it is known if you and your dogs are all fine, and will not be having medical bills associated with the accident.
This is really good advice. An insurance company's incentive is to pay as little as possible, and making sure your health insurance covers health problems instead of them—the car insurer—is one way of doing that. Personal injury is by far the most potentially expensive part of an accident. However, your job is to make sure you use the coverage that is most convenient and cheap for you.
Definitely get checked out and document all of it. There's a very good chance that you'll have serious soreness for a few days at the very least, and you often don't notice it right away because you're shaken up and the injured soft tissue hasn't had a chance to get angry.
I hope you have terrific insurance so you can pay your deductible, get back on your feet and on the road, and wait for your insurer to sue his so you can get your deductible back eventually. But even if you don't, you can go after his insurance—or even him directly if he's uninsured/underinsured. We actually got $50 and $100 money orders every few months for a couple of years from a woman who rear ended my fiancé because she was not insured at the time and a judge made her cover his $500 deductible. The rest of the repair was covered by his insurance for uninsured/underinsured motorists, which means she may have been on the hook to his insurance company too.
Different states have different ways of assigning fault, and I don't know Maine's particular laws, but typically, if it's 100% the other driver's fault, you are entitled to walk away with no financial losses. Sometimes you have to pay a little hardball to do it, for example if your insurance lowballs you on the estimate to repair/replace your car or if the other driver's insurance is slow or unwilling to pay back your deductible.