If you don't have an Epic Games account, you should make one to take advantage of their weekly free games. Thoughts about the company aside, you occasionally get access to some great games like Borderlands 3 and Prey.
I recommend Daniel Mullins games if you like games that challenge the forth wall. Pony Island and Inscryption were fun. I've bought The Hex but haven't sat down and committed the time to it yet, but it was very highly recommended to me.
If you like games like Undertale, it's sequel Deltarune is free on Windows. Two chapters out so far.
If you happen to be a Pokémon fan, it's not really AAA stuff that needs a gaming machine, but I recommend Pokémon Reborn. It's a fully complete fan game that I've been following for years during development. It's also free to download and supports online PvP and wonder trade.
Congratulations on your gaming pc!
I can relate to anxiety as a coping mechanism for undiagnosed ADHD. I can have sudden flares of panic if my mind wanders onto random topics and suddenly I'm wondering if I've left x at home or forgotten to lock my car door (I forgot a couple times...). I also do pat downs of my pockets and rummage through my bag to ensure something is where they're meant to be.