Any settlement would be for the current fair market value of your car. Even though your car was in excellent shape with low miles, it is still going to be looked at by the insurance company as a "used" car and they'll pay off to the amount it's worth at the time of the accident.
There may be additional compensation owed to you as a result of this incident. It may be worth your time to consult with a personal injury/accident attorney in your area to see what other settlement arrangements you may be entitled to. Don't sign anything from the insurance company without doing this or you may be signing off on any other claims.
Mr. Dane has given you good advice. I would be surprised if a collision severe enough to total your car did not injure you at all. Even a relatively minor injury can net you some cash to put up a down payment, so you should talk to that lawyer ASAP. Good luck.