Hah, you sound like me. I've been an avid gym goer most of my life and most days, getting there is a slog. I'll be cursing myself out for the first ten minutes (this sucks, I'm hungry, I wanna go home) but then, usually, the ENDORPHINS kick in and suddenly it's, "Awwwwh yeah baby! Gym kicks ASS, BABY!"

If I'm there for more than 10 minutes and still haven't hit the endorphins, I tell myself that day wasn't my day, and I'll try again tomorrow. But most days, I definitely don't regret going. And it sounds like you don't either!