To me it's gambling. If you put in the time to really understand the company and think it's going to grow, it could be worth it. But these are tiny companies, so there's a lot of uncertainty.
Your Verizon router is the farthest "outside" your network. Your firewall will be 'inside' it. When you connect them, you're connecting the router's LAN (inside) to the firewall WAN (outside).
Very cheap stock, sometimes not even on the "stock market" (exchanges). They're very risky because the price changes are huge. E.g. if it goes from $0.02 to $0.04, that's double your money.
But similarly it can drop fast. It's hard to sell because not many people trade them (i.e. they're not liquid).
When you don't have a lot of money, you often get hand me down clothes that don't fit. You then make do with what you have. And if a group in that situation adopts it as part of the culture, it can become cool and starts to be taken in fun directions.
Look at ripped jeans. It used to be a sign of poverty (you can't get new jeans and your parents can't fix them?), now they sell it as a feature.
That said, it's no more ridiculous than ties and buttoned collared shirts. Asphyxiation is a weird cultural fashion.
That's the thing to fix. Not the lists. Not the tasks. The mindset that causes the anxiety
You don't have to be doing the right thing at the right time. It's ok if things are missed.
You're here now. You're you. Are you or your house literally on fire? If not, then you're ok.
Obviously this sounds like a horrible way to live, and it is if you do it perfectly. But anxiety is a spectrum and you're all the way to the right. You need to force yourself to practice going left until you can be in the middle comfortably.
So try it. Stop the list. Accept where your are. And realize that the world didn't explode because you missed something.
I know you're looking for self-hosted, and I hope you find it. But in case you don't, the free tier of calendly might do the job. I used to use it when I was job hunting.
Sign here, initial here, and put your labia print here.