How to prove the existance of nobody, Like someone made up.

I told my fiance a really really stupid lie, and I am stuck because I cant prove that nobody existed. How can I prove to him that no one does? I have no name, no contact info, NOTHING! What can i do? Please help me. I love him so much. I cant believe I got myself into a stupid lie. I always do this to my self.... I am so stupid.

Ok I am telling the truth, It is the truth that nobody existed. I was retarted and lied about someone existing, I said that I had a one night stand with someone, but I didnt, I have no idea why i lied about it. I should have never lied about it in the first place. I cant leave my fiance because I love him and he is my world and I should have never lied to him in the first place. But how can i prove the non- existance of NOBODY?

Oh yeah, and I know that I am stupid for lying like that. I know this. But please help if anyone can... Please...