Fix my house completely. Buy a better house and start investing and flipping. Then at this point, I'd blow some cash and short Reddit right after IPO.

FIRE. And maybe a pizza.

Everyone's all "stuff to make world peace!" but I'm gonna be honest with y'all.

A lot of old video games. Like a catastrophic amount of them.

Property. What I then do with it can be decided later.

1. Buy a big mansion/estate somewhere quiet in Scotland
2. Hire staff and carers
3. Fill mansion with the CFS/ME sufferers who are in awful situations and give them somewhere safe/peaceful to exist.
4. Rinse and repeat to how many such facilities that much money can support.
5. Leave enough in trust to keep the facilities open.

I'd go to an electronic store and buy everything I want

Start a nonprofit open source IoT hardware company. Internet-connected smart devices and appliances are cool, but not the way they are implemented now. I'd base everything on common hobby chips like ESP32, AVR, and STM32. Every single device would have a completely unlocked firmware upload port.

Controlling shares in smaller mining, green energy, & electric component(motors, solenoids, etc) stocks, and merging them together for vertical integration. Machinery, logistics, & other production stocks, merging into a separate conglomerate for vertical integration. Cargo boat manufacturing companies who specialize in low emissions. Politicians to get more subsidies in those areas, and promote my business practices while penalizing others.

Supply, production setup, logistics, I might throw in marketing just so they REALLY don’t have to go to anyone else. Any business who doesn’t want to worry about the dirty work will go to me. And they will listen to me..

Buying stuff is how you stop being a billionaire.

I'd do all the things that most people would do. Pay off debts, help out family/friends, invest, donate, etc.

Other than that, I'd buy a castle. Something like this. Living in such an old place like that with all the history associated with it seems really cool to me.