I need to ask you a few things so that I can help.
Plug the Kindle inso we know it has a good power source.
So press or slide that button in the ON position and hold it there for 45 full seconds.
Your Kindle will either have a button that you push to turn on, or a slide that you 'slide' to turn on.
This will reset the Kindle and hopefully fix your glitch.
Try that first.
Then we can start to figure out the password issue.
Let me know when you have done that.