Hey badsal
i didn't realise you posted this until I finished reading it.
I think the most important thing for you to do right now, if you can afford the time financially and relationally, is to take some time away and go on a retreat for yourself. Your relationship with your husband is in a very bad place right now and it is most definitely affecting your children because they can see how you treat each other. They will be getting mixed messages about what to expect from you as parents, what you expect of them as your children, what they should expect from deep, important and meaningful relationships, or for that matter anything that seems dependable, reliable, truth or solid, in the future. You are your kids world, and their biggest influence (whether you are active in their life or not, it is an influence of some kind) and the relationship you have with your husband will be one of the most important things that shapes your children's worldview and what to expect, cherise, fear, etc.
I'm not sure where in the country (or world, for that matter) you live but there is undoubtedly a retreat center somewhere near by (within an hour or so) if not a really nice bed and breakfast. If you can afford it you might considering flying out somewhere, a lot of tavel companies on the web and otherwise have really good last minute deals that sometimes include lodging.
I feel like you need to spend some time alone, pampering yourself maybe, and be really confrontational with yourself and really honest with yourself. Ask yourself : what makes me sick? Does he smell? Is there a physicall odor or lack of cleanliness that is turning me off? Or is it something immaterial like something he has said to me, or not said to me? Done or not done?
Does it even have anything to do with him? Is it because of something I have done that has some how turned to me being repulsed by him? Is he a bad father or husband and that turns me off?
Search every possible road and trail and even things that don't seem obvious.
You mentioned that you and your husband have grown far apart. Have you ever realised that you have been spacing out and tried to follow your thought process backwards to see where it started? Try the same thing with your relationship now. What repulses you? When did you first start noticing it? How long have you felt that way? Did it come from a fight you had a few months ago? Last year? A few years ago? Did you have expectations of your husband as a provider, as a lover, as a friend or father that he hasn't met that disappointed you and has maybe led to this? More importantly, did you have expectations of youself as a wife or mother that you haven't met and that underlying failure has sickened you and affected your intimacy with your husband?
Asking all these questions is what I like to call a "trip in". You're taking a journey to inward things rather than wondering and stressing about outward things. The outward things can be signs to roads inward, but there is some thing (or a few things) that are keys--that have cause this reaction and you need to find them and use them to "unlock" what's going on to understand it and change it, if you want to, or help your husband change it if that's where it needs to go.
I don't know if you believe in god (i do), if you do it helps to ask "show me where this stuff is coming from, make me aware of it--how it started,where it comes from, why it makes me react like this". It's healthy to do this "trip in" fairly often, especially in situations where something makes you mad and you just explode. For example: I get really mad when i'm watching tv with friends (guys included) and there's some skanky women on a show or commerical, or some really offensive joke (sexually oriented) and no one says anything like "that offends me" or worse, if they laugh about it or enjoy it (like last super bowl some guy friends of ours were cheering and whistling at the cheerleaders and I was super offened). Now, on the surface it may just seem like i'm super uptight or legalistic. But a good friend of mine challenged me to find out why it bothered me so much. After doing some searching in myself, asking god "why does this make me so mad?" I realised that it comes from having been sexually abused when I was younger. I realised that it was my defense, that in situations like that I had to make it know that I was offended and expected other people (men specifically) to agree with me or say something before I did, because I wanted to know that I could be safe with them, that they wouldn't hurt me or think of me in a nasty way.
This may not apply to you at all in any way shape or form, but it was such an eye-opener for me.
Maybe something happened to you when you were growing up and your husband has reminded you of that and it makes you sick. Maybe you've done something that reminds you of your mother, or the relationship your parents had and it makes you sick.
Maybe your husband brings out an attitude or behavior or pushes your buttons in a certain way that makes you respond in a way you hate (like having an affair...I don't know why you had an affair and you don't need to tell me). Like today, I was signing my name for something and I wrote the letter *exactly* like my mother does, I couldn't have gotten it more perfect if I tried, and it made me angry, disgusted. Why? Not just because I don't want to be like my mother, there's more to it: my mother was no mother at all, she was never around, I don't want to be anything like her, so that was something that set me off.
See what i'm getting at?
Let me know if you're interested in trying it. If you're not it's for a couple reasons: it would take too much energy (i'm slightly anemic and most things take too much energy!

), you don't have the time, or you just don't care.
I want to challenge you that if you really care about your husband as a person (like I said to ocean re: his wife), if you really care about your kids, and honestly, if you care about yourself having any shred of integrity as a wife, a dependable mother, a reliable friend, you will consider this and do what it takes to find out what is disrupting your intimacy with your husband (on a sexual level but also on an emotional and relational level, since you've been so far apart for so long).
Let me know if you want to walk through it, or have someone to bounce thoughts off of. I don't know you, but your heart is important to me because you are a person just like me with fears and hopes.