Wow this sounds familiar, mine told me if I hadnt of gotten pregnant he would have left.
My advice RELATIONSHIP COUNSELING.............
You both need to be honest with each other, ask him if he really want to be with, if he is feeling tied down its going to cause more problems after, such as cheating or leaving you empty handed. Both of ytou should write down the pros and cons of each other and work on it, he cant expect you to do everything, it takes two people, if you cant work as a team it usually fails, if not now then maybe five years from now.
It take two people to fight, two people to have sex, so both side are pretty much equally to blame but what has been said to start it and if you want him to be honest than you can get mad if the wrong thing comes, men and some woman have a tendancy to be more blunt.