Shake, that's terrible! I hope you're ok. Cars are always worth less than people...
I'm no expert at it, but your insurance company's adjuster will give you a pretty good idea of the damage. It may not be totalled, but if the insured value is only $15 (seems very low to me) then that may be the case.
I'm not sure whether or not they let you hold on to the car if they give you the write-off value, but my guess is that they will not.
I would suggest you take someone with you who is VERY knowledgeable about the car to have a look at it. Damage to the sub-chassis may not be worth putting it back on the road.
Hopefully someone more knowledgeable than I will have some solid ideas for you...
Good luck and let us know how it goes!
Don in Germany