Invalid username

Hello,

Our website was created 5 years ago and I have been able to use WordPress to update ever since. Recently when attempting to log in it says that my username is invalid. If I use the forgot my password function it still claims that my username and email are incorrect. After reading other posts I thought that maybe our site was hacked but I have been the only admin user as there has been no changes to the site, it is still functioning. I created a new account in order to post this to the forum. When contacting GoDaddy (who hosts the site) they have been very unhelpful and wordpress.com was unable to help so I am stuck.
Thank you so much for your help.

The page I need help with: [log in to see the link]