Kath, saying that your H is "selfish" would be an understatement. What you are describing is a man who has strong traits of NPD (Narcissistic Personality Disorder). I notice that you were able to identify with some aspects of my description of a person having strong traits of BPD in my post at http://talkaboutmarriage.com/anxiety...tml#post179253
. Both NPDers and BPDers share some traits. One is that they typically have an arrested emotional development, leaving them with the emotional development of a four year old. That is believed to be caused partly by heredity and partly by an injury to their emotional core occurring before age five. Other common traits are their narcissism, fear of attachment, and fear of engulfment, which occurs during intimacy. The fear of attachment, for example, seems to show up in your H's treatment of your children (his step kids) as strangers.
On the other hand, there are important differences between BPD and NPD traits. Whereas BPDers are very unstable, NPDers are stable. Moreover, whereas BPDers usually are caring, NPDers are not -- although they often do a good job at pretending to be caring. If you would like to read more about folks having strong NPD traits, I suggest you read Shari Schreiber's description at GettinBetter.com's NARCISSISTIC PERSONALITY FORUM
I encourage you to read about NPD because, if your H has strong traits of it, it is easy for anyone living with such a person to recognize the traits. It is easy because all emotionally healthy adults have all of the NPD traits, albeit at a low level. Not surprisingly, NPDers have the same basic set of human emotions and primitive defense mechanisms that the rest of us have. So the traits should sound immediately familiar to you when you read about them. Identifying the traits, then, should be easy.
What is difficult is determining whether those traits are so severe as to meet the diagnostic criteria for "having NPD." More difficult still is knowing how to treat NPD (in the rare event an NPDer should actually seek treatment). Hence, only professionals can diagnose and treat the disorder. Significantly, I am not a professional. Rather, I am only a man who lived for 15 years with a BPDer. Based on that experience, I agree with the other posters who told you that living with this man likely is seriously damaging not only to you but also your children. Please take care, Kath.