We've been dating 5 years,engaged for 6 months. He's 39 I'm 26. We had a break due to our problems, for around 3 months, I was adamant that things were finished because of his behaviour, selfish, never calling, no commitment etc etc. We had long talks about our relationship and he said he would change and that he really wanted to be with me and settle down, get married and start a family. We got engaged at christmas and moved in together(his house), His house is on the market and we are currently looking for a house to buy together. However after the initial few weeks things have gone down hill, he makes no effort at all, no affection, sex is like once a fortnight if I ask for it! The only time he kisses me or tells me he loves me is when he goes to work. We both have busy social lives and still do our own things, but we spend a lot of time together and all he wants to do is sleep or watch TV, If I suggest sex he's always got an excuse, tired, busy, just eaten etc etc. I've tried explaining how I feel, I've cried, screamed and shouted and nothing gets though to him. It's like he just shuts down. I've suggested councillor/doctor but he says there's nothing wrong with him he just doesn't think about sex that's all, and that I'm too sensitive.
Any advice would be gratefully received as I feel like I'm wasting my breath trying to explain to him how I feel.

You might want to rethink buying a house together and marriage. Your previous problems have obviously not been resolved.
If sex is important to you and not to him and he thinks you are whining when you ask about it, a marriage is not going to work.
He maybe so comfortable in the way things are he sees no reason for them to change.
If he does not want to go to counseling to try and fix things, you may be waisting your time with him.

My first thought was that he's cheating. My ex stopped sleeping with me as much, because he was afraid I could smell her on him. And you did she he had commitment issues before..