As for your missing passwords issues
I’m sure you might have your primary gmail or other services address(access)
Use the forget password feature and set the new passwords for all of the sites which you have saved passwords.
Sites which are important will be stored in your mind, as for other sites if you have saved a long list of passwords,-> Dont overthink about it, you will eventually come across the sites if a need for it arised… During that time, you will be able to gain access by setting a new password using the forget password feature.