Ok, so, I did all of those things, and no luck
I reset my password again to something new, at least 8 characters long.
Then I cleared all the browsing data, cookies, etc from the beginning of time and closed the browser.
Restarted the browser, navigated to the archive, typed my email address in the top right login box, typed my new password, clicked login and it just did the same thing as before
I feel like there is something really silly I'm overlooking, but for the life of me I don't know what!