Sounds all to familiar. Feel good about it, you hung with the younger faster rider for longer than you expected. Good job. I did the same thing with a younger faster group at a charity ride this spring. I hung with them up to about 40 mile mark. This ride was on roads I ride every day, and I knew the 18 mph head winds were coming up. I struggled a bit up one hill in that wind and they dropped me like I was dragging an anchor.

I caught them at the last rest stop which is at about 48 miles. Hung with them for another few miles and lost them again, but I only finished a few minutes behind them. I was beat, but I felt good about the day.