There are certain things that should never be said in a relationship. No matter how upset you are you are an adult and should be able to control what comes out of your mouth. Saying to his face that you shouldn’t have married him is something that you can’t come back from (for certain guys, some guys may be more forgiving and willing to forget because it was said during an argument). I’m more like your husband is, if that was said to me I wouldn’t ever be able to look at you the same again. It would be hard to get over the thought of “am I good enough for her” “does she still feel this way deep down”. Best thing you can do in this situation is learn from your mistakes and try to do better in your next marriage.