If you're really looking for an answer (that is, not just venting, which is fine), I'd say "enough" is the point at which you'd look back and say, "What was I thinking to say ?" And then I would remove myself from the situation for as long as I felt I could. The stories you related here are similar to stories I could recount about myself lately. I like to think I usually have enough of a filter so I don't say everything I think. But when very little seems to be filtered out, I know it's time for me to take a break. Not that the situation fixes itself in my absence but it gives me enough time to think about what I want out of the situation and to maneuver accordingly.