I got a Peaceful, Queasy feeling

If I am so fit, then why do I feel like puking after a couple of short sprints and a 30 minute work out?

Warm up - 3 times through - 200m sprints, you go / partner goes. Chad and I pushed it.

WOD:
Part 1 - Cindy - 6 min - 6 rounds even
Part 2 - Push press - 18 minutes to find your 1 rep max. I know what my 1 rep max is and I could not find it today. I got 185 and then tried and failed at 205 twice. I never did fully recover my wind from the above.
Part 3 - Back to 6 min of Cindy. I felt flat out awful. Yet so angry and disappointed at my PP effort. I pushed past 6 rounds and was 10 squats away from completing round 7.

Part 4 - Sit on the curb outside feeling sick to my stomach. Drive home. Shower. Back to work, and still feel sick to my stomach.