Unfortunately, the only way I could find to do this in Liftoff! is by going to Settings > Accounts and deleting each local account by long pressing on it, and then create it again.

Thanks! This is what I did and it worked fine.

I manage to log back in my just by relogging my account. I thought I was banned or something

This seems to be the issue, a code injection using custom emojis. Apparently Lemmy is letting some unsanitized data in, which means that Little Bobby Tables strikes again. Somebody was afraid the attackers had seized control of the whole Lemmy network but federation helps hinder the damage here, only individual instances are affected and they'd have to attack each one independently, a single server service would be fully affected in this case.

Beehaw has fully taken down the server as a preventive measure, i imagine they won't be the last ones doing this.