hi,newbee,
me a 39 year old male marrid for 10 years.I think i can try to understand the thing you are going through.As we get more involved in the tangles of life,we lose interest in many things which once might have been our passion.Sex is one of those things.Better you try to know if anything in his job or in his career troubles him,or he is trying hard to fight back some problem he is facing..trouble in mind troubles sex,I believe.Similarly,think on your part too in the same terms,i.e.isnt it that something troubles you and you are not responding cold in bed..Furthermore,go for longer foreplay and add whatever new to it,e.g.new postures,new gestures,new ways to rub and pat and touch..and,yes,start when you are sure it wouldnt be disturbed by any of your kids..its very important..