glad you're okay and walked!!
I mean I wasn't there, but from experience in a slightly head on crash in a G37, when the rest of the car is perfectly fine... depending on engine damage.. it is unlikely they will total it..
that being said, glad you are okay, you posted at 3:15AM, so you felt fine then, when you read this, that might not be the case, I would get to a chiropractor/hospital as soon as possible for observation, as sometimes, these injuries take time to develop, and when they do, if no action was taken, you're out of luck...
perhaps also get in contact with a lawyer.. pretty ridiculous that they barged into your lane, could have killed you.