In need of reassurance...

I don't know what's worse: DNF or a really really REALLY bad time.

5k track race today. Stopped around 15:30. Couldn't get my breathing down, my legs were heavy and it was everything I could do just to keep going, it was probably around 80 degrees and sunny when I ran, which had warmed up from low/mid-60s and overcast (aka perfect).

I just feel like crap for choosing that route. =/