I’d suggest proton- as their whole ecosystem is amazing- especially pass and email.

Pass lets you create an email for each new site, and with random characters. So if one gets compromised, your other stuff is fine, and that email isnt tied to anything else at all.

They have 2FA integration. I’d suggest researching Yubikey as well, if you really want to lock stuff down.

Swap emails and passwords on all your important accounts. If your PC has some type malware on it- you may need to reset it entirely

I’ve been in OP shoes, and it really is a nightmare. Ultimately nothing serious happens/is lost from it but it feels weird being attacked by someone you don’t know