I really feel for your situation. To think of how young you and your marriage are and to be having such severe problems at this point breaks my heart.
I agree with what others are saying. Plainly put, if the situation continues as is, you will most likely want to get out of the marriage at some point and children will make that very difficult to do. I think that most of us here sense your commitment to family and sense of responsibility to others. This could translate into an unbreakable desire to keep the family together later for the sake of the children but at the expense of your own emotional well-being. I speak from my own experience, although my situation is not a dire as yours and I remain married to a LD spouse.
Has H ever stated to you whether he thought sex was important in a marriage or not? Is it possible that, due to either a natural or induced low libido, he doesn't understand the importance of a full sexual life to a marriage? It could be possible. This is where the SSM book will help. By reading he may see the importance of sex in the marriage from a POV other than yours which may get him to more readily accept counseling.
Get him into counseling, continue work get him to see what he is happening to the marriage but, IMHO, do not hang on for the sake of hanging on.
