I am having this exact same problem (tho with only one of my WP sites) and have tried all the same solutions.
It is not letting me log in and also telling me no user with my email address exists when I try and reset my password.
If anyone can give any advice it would be MUCH appreciated.
Not the best thing to come back to after the holidays! ??
My boss may shoot me! hahaa
Sky (skyandbradd).