I evaded taxes my taxes?

Hello, in 2000 I sold a house for 1 million dollars. I didn't pay the taxes and until recently I had thought that nobody would catch me. Now, they are citing me for a tax auditory for something I failed to give account last year. I know that they will investigate me from toes to head, and I am really scared that they will see that I willingly evaded taxes 11 years ago. Can I still go to prison even though its been 11 years? If so, can you please help me, I am really really scared!?