It appears that the computer is filling in my password with something that is twice the characters of my password.
Are judging this by number of dots or stars in Password box on Login dialog? Because for security reasons, WinSCP deliberately always shows 16 of them (unless you are in editing mode), no matter how long the password is.
It's likely there's problem on the server. Either you password was changed or your account was disabled or cancelled. We cannot help you with that.