Dear bigmistake, I think along the lines of the earliest posts recommending tests for STDs or pregnancy. Then I would take your own words and not keep it a secret. I wonder how DN can be so sure that you will not do it again?
If you tell your husband, he will decide whether to forgive you or stay with you. There are deeds we are ashamed of, and these need not to be revealed to our partners if they are in the past. But I see this (having these kinds of parties, heavy drinking leading to loss of inhibitions) as being part of your personality today, and it affects how you behave in your relationship. Does your husband know you this way?
Also, if it's one of your neighbours, how safe is the secret? You have time to think about this, use that time wisely!