Max paranoia = get computer off of internet

Otherwise, change your passwords, hope you have multi factor authentication enabled everywhere, and pray that you didn't use the same username/password everywhere.

Moving forward, if you didn't already, enable multi factor authentication everywhere you can, and use a password manager like 1pass, Lastpass, or Bitwarden (my preference, open source and has a free version) to generate and keep your passwords.

A good password manager has browser extensions, desktop app, and phone app to auto fill your passwords so you don't even need to know what they are once you go back and have it auto-generate one for the websites you visit. Its a lot of work initially, but once you get through the bulk of all of your accounts, its super easy and you never have to worry about remembering passwords.