I'm thinking of cancelling my wedding.
You must be joking. Why do you want to cancel the wedding?
It was just a drunken idea.
It sounds like there was some hesitation from the start. You should not have gotten engaged if you were not certain that this is the person that you wanted to marry.
But it was so much fun at the time.
I don't think it was right to get engaged just for fun, if you didn't really want to get married. Your partner was probably serious about it, and when they find out you don't really want to get married they're going to be hurt.