Thunderbird can not load E-Mails and now does not recognize my password?

Recently I have been having some issues trying to check my e-mails on Thunderbird. It no longer updates my inbox when I launch it, and when I launch it Thunderbird says it is having network issues. I then went and re-installed it, deleted the user, and tried to re sign in but for whatever reason it keeps saying the password is incorrect now despite the fact that I can go onto the website for my e-mail and sign in there with no problem. I can not post a screenshot of the original issue but now I can't even sign my e-mail in through Thunderbird.