Yes, as others have said here, Hold off from buying games for a bit.
But also, play what you want to play.
I used to be in the same boat as you. Having a backlog the size of my... my.. drawer. But yeah as I've grown older I've also come to realise that I can't have too many story games on at the same times or I will loose on plot and mix them up a bit. What I did a couple years ago was to write all of the games down that I wanted to get through, list reasons of why I wanted to play each one ASAP (to avoid spoilers, length or because it would suit me). That said, you will also realise that not every game are for you. I still got a couple games which I gave a chance but ultimately decided to drop. It should be fun to play games!
Also there are no shame in not finishing a game or just spend some time playing multiplayer. I mean there are countless times I've just said "screw it!" and gone back to a few rounds of Titanfall 2 multiplayer. If its fun why not.
But yeah, Rank them to how badly you want to play them. Sit down and stick to 2-3 games max, if you really don't feel it, drop it, but also consider "is there a chance this slow build up will pay off?".
I don't think that you have burnt yourself out on games. But things goes in waves, there has been weeks when I don't really play anything, then there are weeks when I play more than I perhaps should.