I had something similar a while back Sassycakes and again
a couple of days ago, I was asked by Mozilla if I wanted to
update and save the password, when I looked at the new
password it was 11111111111111111111111111111111111,
I have no idea how long the line of 1s was, but I had saved
it once before and had to edit it in the "Password Manager".
You can try to revert to a previous date if you can, you can check
your password manager if you use one, or you can ask Google
how to open your "Make and Model of Laptop", in "Safe Mode
with Networking", that will allow you to move all the things
that you want to another place, like a spare "Hard Drive", or
another computer, then you can go about cleaning the laptop,
if you have Windows 10, you can get a "Fresh Start", they call
it, they will re-instal windows with the latest version without
losing any data, or pictures, they say, but I would still back it
up somewhere, even the cloud if you have an account.
In safe mode you can run an anti-virus software.
I hope the above helps.
Mike.