Hunny, I often feel just like you do. My W also doesn't monster at me, but she did run for a short period, have an EA, and is cold, distant, selfish, and spends lots of time out of the house. Although she isn't near as bad as some on here, she is still 180 from what she was. Always was the most kind, thoughtful, loving, and appreciative person around. Because of that, I could really relate to what you described with your H.
I think Job is right (she usually is :)), everyone comes from different situations and handles themselves differently. My guess is that sure, some people with good marriages have rough MLC episodes, but I don't feel like that describes my situation. Our marriage was good, and her MLC is kind of mild compared to some I read about here. It doesn't FEEL that mild to me, but she is compared to what she COULD be doing.
Hang in there...you've got this. Just remember that you are the prize. What man in his right mind wouldn't want someone like you who is willing to put up with so much stuff just to be with them. He isn't in his right mind right now, but he will be eventually. You'll either still be there for him or you won't...and at that point you will know what you want to do. For now, just be the good person that you know yourself to be. You are worth it!!