Help please, everything disappeared!

Hello everybody! Help me please! I have done a two-hour work in excel 2007. I wanted to delete a lot of of unnecessary sheets, Google gave me an instruction about F6, ctrl, space and arrows. As a result of my actions, everything disappeared - both data and sheets, just a gray background and nothing else. In the "view" everything is set correctly, nothing helps, ctrl+ z does not work. What can I do to get back my data? If there are some people which speak russian then say me in russian please, because my english is very bad)))