Someone likely obtained your information from a hack and is trying to access your accounts. 

I would make sure your email has a unique and complex password, change any passwords you have duplicated, as they will try to use it to log into anything else with your email, and set up the 2FA on any other accounts you don’t already have it set up on. 

It wouldn’t hurt to change the rest of your passwords, especially the weak and duplicated ones as well.