So here I am with someone I love but I have never been so lonely in my Life!

It sounds a mix of physical and emotional on his part. WebMD "sexual problems in men" search

I have logged off because a related party might read this discussion and I have no desire to hurt feelings. I divorced someone I did and still do love, but the love had changed. The intimacy was gone, it wasn't going to be recovered. It's awfully hard to stay married to someone you no longer wish to be intimate with. We shouldn't have married, we should have stayed friends, but on the other hand, our children are marvelous. Divorce, though difficult at first as might be expected, has enabled us to retain our friendship. Our intimate lives are separate, we don't share information on that, but we discuss most other topics that once would have been discussed during our married life.

Before calling it quits, you both should have thorough physical examinations, and perhaps go through some Imago therapy (do a search for a practitioner in your area--it is based on an old Carl Rogers technique of "mirroring" what the person opposite you is saying).

It may seem counter-intuitive to divorce before a relationship hits rock bottom, but on the other hand, you'll have something left to work with when you come out the other side.

Something to think about.