Some of the browsers we are using today are very deliberate in stealing people's data by asking them to save the password on every platforms they signed in or registered in. I must also confess that I have fallen for that in the past by saving some passwords on browsers. How do we get rid of these passwords on browsers? Does deleting them means they won't longer have access to it? If not, then it's a trap set against users.
It would help if you changed all your passwords. It isn't easy to delete what is stored online. However, changing your passwords will not affect your security. Get into the habit of completely deleting all traces of sessions when you finish working in the browser, clearing cookies before closing. And to save passwords, use password managers with an open source code (for example, KeePass, Bitwarden). Or just save them in a blanket encrypted document.