Oh dear, one should not laugh at your mishap and mess to clean it up, but the way you told it is hilarious! One of the things that I have learned from judging 4-H (50% project 50% interview) is that the most things are learned when mistakes happen, so keep trying.
The recipe you are going to try sounds delicious. I would double check if they accept a cream cheese frosting as it is recommended that it is refrigerated.
Please let us know how you place at the fair. I am excited for you.