Sosad, I can really sympathise with you and I hate to say it, but I can see that my dp and I may get to the stage that you seem to be at at the moment.
Ever since I had my ds I have not been interested in sex, and yes, my dp and I loved sex before and it was the best part of our relationship. In the last three months we have had sex once and the time that we did, it was instigated by dp who said things like "you used to enjoy it" or "I need love and sex too you know".
Obviously I felt guilty by these words and I do know that he must need sex and I feel very selfish at times but although I do love him dearly I just have nil sex drive now and would be quite happy if we never had sex again and just cuddled in bed and went to sleep!!
I don't honestly believe that men mean to manipulate us in this situation - I think it is just their natural instincts coming out - after all, I do believe that men need sex a lot more than women (well most of them).
However, I also don't think that we should give them sex just to keep a happy and harmonious home. It is so difficult because I, like you, feel that I should give dp sex so that we stay a happy family but I have got to the stage now where I can feel it underlying and feel like there is a pressure there to "have sex" and I can't relax with it.
I think I feel even more guilty because I do see some attractive men sometimes and think that I would like to have sex with them.... but when push comes to shove (if you pardon the pun!), I doubt I could be bothered!!!
Good luck - I would try talking to him and tell him exactly how you are feeling and why you are feeling this way and this may take the pressure off, depending on whether he is an understanding kind of guy.