Lost content and theme during update

Hi there, my site was loading super slow (not loading) this morning and so I called GoDaddy for help. They told me to update the application through their website and so I did. When I did this it reverted my blog to back over a year ago – lost all of the posts, content, and formatting from the past 12 months. Literally everything.

I have no clue what happened, they aren’t sure what went wrong or why this happened and now I am so scared that all of my stuff is gone and missing and I can’t get it back. HELP!