If I have to draw diagrams, I use D2 https://d2lang.com/
It’s a very simple to use code to diagram language.
It has plugins for vscode and obsidian.
It’s open source that you can run locally, with the exception of their proprietary visualization engine. But I don’t use that one, just use ELK.
A VPS with fail2ban is all you need really. Oh and don’t make ssh accounts where the username is the password. That’s what I did once, but the hackers were nice, they closed the hole and then just used it to run a irc client because the network and host was so stable.
Found out by accident, too bad they left their irc username and pw in cleartext. Was a fun week or so messing around with their channels