Hi Eva,
Being in a couple is so extremely hard even when you love your partner that I'm not sure why would anyone stay without love. Why do you want to remain married to your husband?
The Usual reasons I'll respond to are:
1. Financial - yes, it's easier financially to live together, but that's not a good enough reason to stay. Or, you can decide to continue to live together for a while even after divorced and seeing other people. Obviously you wouldn't do that because money isn't a good enough reason to suffer seeing your ex with another person on a daily basis, but then why isn't the daily suffering of not having a better life enough reason to separate.
2. The kids - I, personally, don't believe in sacrificing your life for your kids. If you sacrifice your own life for them, they will learn from you and sacrifice their happiness, and so on, and like that no one is happy. If they will see you striving for happiness and living better separately they will strive for happiness.
It's not easy for kids, but it is also much better for them to grow up in a house with a lot of love in it than one with a bad relationship.
3. Momentum - People very early in life, sometimes already in their 20s, feel they don't have the energy to start over and stay with a person they are not so happy about. The idea of dating again, of restarting, seems so scary to them that they prefer the mundane life of staying still. It's true that it will require a lot of energy to restart.
4. They still love their partner. This is true in almost every single case, on some level. But some level isn't enough for a happy life.
5. They tell themselves that "even with someone new there will again be similar issues." The
Monogamy discussion is a nice example of issues that will repeat. It's also true that if you're hungry and you eat you will be hungry again, but this doesn't mean that there is no point in eating. Also, one gets better at solving and mostly at avoiding problems. It is easier not to go into a bad situation than to correct one.
As you can see, none of these reasons seems like a good reason to me. But this is based on my belief that it is good to be in love. That it isn't true that you wouldn't be happier in a more loving relationship.
You say: " I don't desire any other man, and I'm not inclined to look outside of the marriage for someone different or better."
The problem is that you don't have to. If you separate you might have to, and you might like what you find. Well, you'll also hate what you find because you'll find a lot of jerks, but hopefully someone good as well. It's not a question of "better." It's not a comparison, it's to find someone you will love and will be happy to be with.
And him, you can understand he wants to touch someone, he wants to be with someone, and if it's not you are you ok with it being other women? Are you ok with an open relationship? That won't solve everything but might help. Do you trust him enough to be careful and safe so you won't get infected, etc.
People like being touched, they like touching people. It's true that one can find other outlets for this, and in fact men often find work as a replacement for touching (whether they like it or not).
Of course, a new relationship will bring with it its own troubles and heartaches, as you very well know. In fact, you know everything that I'm saying, and yet I think it's good to say in any case. But, I think, that it's worth to live and strive for happiness rather than accept a kind of passionless living arrangement. Passion is a very powerful energy source, more powerful than food or anything else, and as you'd be weak if you never ate, it's harder to live well without passion.
(I should mention that I'm not only talking to you, Eva, but to a significant portion of the population who probably are/were/will-be in the exact same state as you. Specifically about you, I have enjoyed reading your posts. You are a very smart person, I hope you figure it out.)
