I am someone in your position. He wants to make love to me, but it is unfortunately yet another lost skill. I tried facilitating him for a while, but I got no pleasure from it and, in fact, he used to (unintentionally) hurt me. He has also changed and I no longer see myself as a wife. I am his housekeeper, lodger, nurse, whipping boy and companion, but unless he wants something from me I am no longer even in his mind - I am like someone he met at a bus stop.
Since then he has turned to solo sex, but it seems (far from dying down) to have escalated over the last two or three years years - first with using porn (and this was a complete change for him), then with obtaining viagra (to "enhance" the porn) and now with it happening outside.
I dont know what the answer is, but I know that explanations and reasoning dont work - he is unable to understand what the problems are and thinks that what he is doing is normal, so it is me that has the problem!