You're hitting taper time. Relax, make sure you don't injure yourself, do some short rides with a few sprints thrown in to maintain fitness. Maybe do a little figuring out what food you can digest well during a long workout. Make sure your bike is all ready to go and that you know what you need to know to pack/unpack it. Fix any things that annoy you while riding about your clothing/carrying food on your bike/etc.
You have the fitness you're going to have. Now the game is mental, and if you can convince yourself you will be fine, then you will be fine. When I was 12, my dad and I signed up for a two day, 78-miles each day charity ride. Our longest training ride was 30 miles, which I'd never done before. (My dad had other cycling experience, but I'd done a few 20-mile rides and one 30-mile ride, and was not yet really into any other sorts of athletics -- I didn't really know how to train or pace myself or anything.). I had a great time.
Stop at every rest stop and eat/drink/fill bottles and stretch -- you won't feel like you need it at the first few but you will be a much happier rider later in the day. Reapply sunscreen more often than you think you need to. The toughest part for most people in a century is around 60-80 miles -- you might feel like you're done. You're not. Eat, drink, stretch, take five minutes to lie down in the shade with your feet up, you'll be fine. Remind yourself why you're doing this; if it's in honor/memory of someone, pull out those memories then.
Starting the second day will likely hurt, especially your rear end. Coat anything that's chafed in chamois cream (if you don't have any, find some NOW), and any sit-bone bruises will stop hurting so much after 10-20 miles, I promise. If your little fingers start to tingle, try to move your hand positions around/shake them out regularly; if they go numb they will recover, it can take a few weeks.
Last edited by antimonysarah; 06-16-22 at 07:39 AM.