There was a new breach found last week and reported by Troy Hunt on January 17, 2019. This one is a massive breach where a collection of emails and passwords of over 2.5 billion rows of combinations. There were over 1.1 billion of these as unique combinations found possibly due to emails being in both upper case and lowercase. There were a total of of over 700 million unique email address with passwords.
Perhaps you are no longer using a particular email that was found in the breach. Or maybe your password has been changed. Chances are you are or were a little lax about your passwords and re-used them on different sites.
You can use Troy’s site https://haveibeenpwned.com to check to see if your email has been found in any breaches. You can use this page to check to see if a password you are using has been in any breaches: https://haveibeenpwned.com/Passwords
We recommend you use a password manager and let it generate secure passwords for you. You would only have to remember that one password and can have access to all your passwords and sync them to your devices. Some managers even offer storage of sensitive documents.