I think I understand where SS is coming from. I , too , was stuck in a similar situation. It started after the birth of our first child and me being honourable and never pushing the issue let it sit for 3 years until I went down with major depression.
It wasnt just the lack of sex - it was the lack of the secondary aspects of closeness - cuddles, massage (she would let me massage her, but not the other way round) - the relationship was mainly give and take - I would be trying to do many things for her and get nothing in return . She now says that she was afraid to reciprocate in the small things leading to her pushing me away.
There are many , simple, things that she could do to help you IF she was fearful of sex.
In case your wondering, after a spell on Prozac , I decided that counselling was a better option and eventually talked through how to talk to my wife about the situation . After a few weeks of talking we got to the point where she would help me masturbate and after a few more weeks we had a occasional sex life .
This isn't an either or situation - there are shades of grey in between where she can meet you .
However , no amount of ignoring the situation is going to make it go away . You have to talk to her directly about this . Turn the tv off , put the sprogs to bed and spend an evening talking . Tell her that you want to be closer , more emotionally involved .
I can recommend the Relate 'sex in loving relationships' and the other Relate books .
Be careful you don't fall into the same depressive cycle that I was in - the world looks incredibly bleak and hopeless then you are down there .
Good Luck
James