Lost my game !PLEASE HELP!

Hi,
I lost my game because unity froze up. So I tried to close it (my game is saved in my files on my computer hard drive) I managed to close unity, but when I went to reopen it my game was removed from my projects, I don't know how to get it back. I have tried adding my work with my files but it just took me to a blank game with nothing in it. Any help is much appreciated as I have worked hours making the game and for it to just disappear is very frustrating, (I was using a karting template if that helps)
thank you

Please help me get my game back
(I don't know whether this is a bug or not)