Wow! That run sounds just GRUELING. I actually think you should be pretty proud that you finished that race. Ugh, three flats, too! Sheesh. I'm glad there are parts that felt good, but more than that, I'm impressed that you stuck through that whole run and that you're okay.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks