How do I stop second guessing what I say in conversations after the fact, after i walk away?

Are you more concerned over WHAT you said...or the effect it may have had? Having a conversation is an art in itself. How so? We are trying to convey thoughts, feelings or ideas through words and expression. This skillfully requires intent, observation and....listening. All of this comes together to make the conversation progressive. Often times we will fault ourselves over what we may have said or not said...how we said it or our body language, when really the person we were talking with has much to do with the end result. If they are just sitting there...either rudely ignoring you or not offering much input...it will kind of leave one "second guessing" as to how it could have come out better. The moral of the story is? We often say things best when we say nothing at all...but when our hearts truly have something to say the message will be clear...let there be no doubt about it.

i found the solution to be to think about what i say beforehand to avoid remorse later. but i get what you mean... its all about confidence in oneself

It seems to be a confidence issue. We all second guess ourselves at times but doing it too often isn't good. Try thinking your thought completely out before you say it. Think about exactly what you want to say, that way you will have said everything you want to say.

I don't know. I have done it all my life and always seem to find some way to humiliate myself saying or doing something stupid or inappropriate.