The worst Mother in the world would not know they have done something that has caused a little confusion for the kids Purply. You are not the worst Mother, far from it by the sounds of things.
I am sorry, but you had a few drinks, so what? You are allowed to have a good time when you are on holiday, it's not a big deal, honestly. (I know you shouldn't on the meds as well) Please stop being so hard on yourself.
Ok, how old are the kids? At some stage you would have told them about the first hubby, so you told them on the weekend.....you didn't mean to, but you did. That happens, we all can say too much at times, and I know had you not had a drink, you may not have picked that time to do it, but now it's out.
Sorry, but you are being way too hard on you, you had a good weekend way, you are allowed to have a holiday.