Ouch - that must have been absolutely gutting. I definitely did feel the same way - there was a bit not long before the final stop where it was a 2 mile flat stretch straight into a headwind and my legs felt like they'd died. Looking at Strava, I averaged 11.5 mph along that road, compared to the 15.5 I'd done on the rest of the course (and the 16 I was aiming for); it was pure purgatory. I stopped for almost quarter of an hour at the final stop (85-ish miles) to recover, which considering there was nothing there to eat and the water was being topped up from a garden hose, it wasn't exactly a thriving metropolis of fun! Took all the willpower in the world to get going again.
The worst thing is that I'm guessing you had to pull out just before the final hill. Sorry to say, but once you were past that the pain was over - firstly the downhill was lovely and then as soon as that was complete, you had two right turns immediately to put you on the road to get back to the finish and it was a tailwind all the way along there and back to base. I thought based on the previous 20 miles that my legs were shot - it turned out they were actually fine but they just couldn't fight the wind, as I somehow set PR after PR on that final stretch - last 2.5 miles covered at over 20mph; couldn't believe the difference!