this can be saved!!
sex is a massive issue for loads of knackered parents - you are not alone!
can you try to reassure him and say you do love him but dont want sex as tired, fed up etc
then try and get lots of time to yourself to recover, eat well, take vitamins etc
get babysitters every week whatever it takes and do nice things together - cinema, meal out, or whatever you like - dont talk about kids/splitting up etc!
hold hands, kiss on check, give compliments during the day when it is unlikely he is going to want sex so it feels safe
take it a step at a time and show affection in other ways.
there is a great sex book i read by tracy cox and one of her best bits of advice was 'drink'!! lose your inhibitions and give it a whirl - dont think too much about it, just get on with it.
not sure if that helps or not, but it worked for me xxx