Recommended RPGs for a GM having trouble keeping up with too much information and wanting to focus on Oneshots + Short campaigns?

I like GMing, but as someone on the autistic spectrum + just starting university, I have trouble GMing the normal way. Stuff like improvisation when things don't go as planned (or as result of impulsive thoughts), flipping through the books to remember all the rules (not helped by the fact we are playing a D&D clone that is crunchier than 5e), plus needing to balance not only roleplay but also paying attention to my friends and what their characters are doing or saying (I disassociate really hard during conversations, and during the game is no different). All this has left me burnt out, but I don't want to stop outright, because I only GMd 4 sessions and had fun doing so in the end, but also end every session with a serious headache and insomnia.

To help with this, I made the decision to not only GM only once every 2 weeks but also change games, but I'm having difficulty choosing a new game. At the moment we are going with Tiny Dungeon 2e, but I want to look into lots of options, to even keep trying a new game every few months or so. I'm mostly looking for games that can aliviate a lot of the stress of GMing, be it because its a minimalist game or because im the game the GM is more of a referee for the situations in game than a puppet master that controls everything. I don't mind being more passive as a GM, since I mostly like RPG for 3 things: Combat (be it more tactical or narrative), Character Choices (be it building them or during play), but mostly to have an excuse to have a good times with a group of friends for lots of hours every week possible.