Dear John,
Thank you for your candidness and for opening up a subject area in which I am sure that you are not alone. I know that we personally have had to struggle with differences in this area, though perhaps not to the degree that you have. Many couples find that interest in sex fluctuates with childbirth, illness, stress and other factors affecting things.
One of the things we have found helpful has been to be able to discuss how we feel when we are particularly aware of our differences and to discuss the things that help us to be more open to making love. In particular seeing lovemaking as something that runs through the whole of the day and the way we respond to each other has been helpful. I have found it useful to try to understand how David feels when he is desperate to make love and he has tried to understand what it is like for me when I don't. It took us some time to get to talk at this level of openness and to be able to stand in each others shoes.
Understanding the different ways male and females respond has been important, the male as a “gas cooker”, ready to go, the female as a more slowly warming up electric oven. Men being stimulated by what they see and women often needing time to relax and feel close emotionally.
I believe that understanding some of these differences can help to bring a couples sexual needs and responses closer together. I don't think seeking relief in pornography is ever beneficial to a relationship. There is a real danger that is can lead to addiction and replacing the wife by the "others". It can blunt the desire for the husband or wife, just as surely as having real physical partners can.
On the other hand I see making love as a gift one can give to the other. The one who has the lesser appetite can make a decision to love by making a decision to make love for the sake of the other. By their initiating love making, the cycle of pressure and retreat can be broken.
Similarly the one who has the greater appetite makes a gift of love to their partner by not pressurising them.
Of course there can be fear holding us back from intimacy and keeping us from talking about our sexual desires or lack of them. There can be past experinces that affect our attitudes and our expectations of each other. These can be difficult to talk about but it can be helpful to do so.
I believe that sexual love is at the very heart of marriage and something that God wishes to bless and sees as holy. He can and will give you the grace to find a way forward especially if you submit to His will and keep from paths that are not pleasing to Him.
As far as books are concerned,
The Act of Marriage by Tim LaHaye and the
Act of Marriage after 40 are both good books in this area. I hope this gives you soem food for thought.
Liz