I would suggest from experience that if you don't get some positive communication going and things don't change the earlier you get out the better.
Just would like to say though that you are describing how YOU feel about him.
Does he know this ? How does HE feel about you , the kids , the marriage in general ?
Do you even know ? Have you suggested counseling ? Do you really want to give up on the marriage ? These are some of the questions that I think need to be looked at before you make a possibly rash decision. If everything you say is true about your husband then I don't think that's the kind of person I would want to be around much longer.