Verity
If you were sober, then... what excuses really are there? If you did it because you had feelings for him... I'm sure there's nothing wrong with that, but thinking that that made it okay to go through with a ceremony? You're a grown woman and a mother, surely you have better judgement about what to be spontaneous about?
I think an annulment is the wisest choice, still. But that's not stopping you from assessing your feelings about him and coming to terms with the possible revelations from that. Even if you want to be married, I simply don't think that was the way to go about it.
Then again, it is your life and your life only, and in the end, the decisions are all yours.