Congratulations on a hard-earned birthday ride!
Your post reminds me of an event last year when I got caught in a thunderstorm about a third of the way through the ride. A friend and I ducked into a police substation to ride out the storm. He had the foresight to bring a rain jacket and was OK. I brought no jacket, got soaked, and was shivering uncontrollably from stem to stern for about 20 or 30 minutes while I was inside the station. I can relate to your situation and salute you for your determination to finish the ride. I vote that the miles should count!
I've since purchased a good rain jacket and will add some rain pants soon.