I noticed toward the end you mantioned "1st time off the track".... Well in racing / track days etc. usually is not a matter of "if", be a matter of "when". The good news, as you able to drive out, I would anticipate that you had a lot of damage? And MOST Important you and the passenger appeared to be OK.
No damage other than one cracked rear diffuser. Luckily, I had the car wrapped earlier this week so no paint damage. I have removed all the belly pans and the car looks unharmed. My ego is another story. :bored