Welcome aboard to the Century club! It's a great feeling to meet that goal, isn't it?
Great advice already here in reply to your 'what do I do to recover well post-ride question'. I'll just reinforce how important it is to eat within what's called the magic window afterwards: about 45 min - 1 hr after finishing your ride. Even better if you can include some protein in your post-ride meal too.
I didn't know about the 'eat within an hour' rule of thumb, until I had been riding a bit and got into the habit of heading to the shower first (doesn't brushing your teeth after to get rid of all the grit mouth feel great too?!). Then I started to pack a cooler with a recovery drink (I use Cytomax during the ride and have Endurox waiting for after long rides) and snacks (tuna sandwich, PB&J on a bagel or the like, unless there's a post-ride meal already waiting), I found that I felt much better. The recommendation to stretch after is great too and it's really more beneficial to do it post-ride; during the later miles I'll sports massage my quads, calves and glutes to keep them from tightening up and pooling lactic acid. Just jostling the belly of the muscles really, nothing deep. It only needs to take 30 sec or so roadside and you'll have fresh legs again to keep going. You're right about the "mind game" part too; at some point it all becomes mental and then you can play games or count or do whatever to get to the finish.
An easy spin the next day is perfect...if there's a flat trail or easy loop you can do, not even looking at mph or heartrate during it, but focusing on a nice, easy, cadence, that works great.
My PT recommended all of the above and it's worked great for me. I remember completing a double century in 1 day a few years ago, for the first time, following her directions and I amazed myself and some buddies the next morning, when I took an easy spin then walked to an outdoor concert and picnic, feeling super.
Check out whatever works for you; your body will let you know what to keep doing and what to discard. Happy trails!