I wouldn't be so sure that no-one is being hurt, Millie. And just to be clear - I do think if he had an affair, that would be very wrong - and while you might not blame him, loads of others would - and rightly too. Having an affair is the coward's way out of a marriage.
I wouldn't pay the slightest attention to friends or family who are alluding that this marriage is normal. It isn't - and absolutely doesn't have to be this way. A marriage without intimacy sucks - it's a waste of life and a terrible example to children, who learn all about forming romantic relationships from their parents and other close adults.
Often people will tell you this is normal, because they have too much invested in that belief themselves. If they dared challenge their own relationships, they would have to make some difficult decisions too, so they go on deluding themselves and others that this is life and that we should all get on with it.
No-one should live a life without passion, intimacy and great sex. I hear what you say about your pregnancy hormones altering your behaviour, but you also admit that in 9 years, you have hated the way he's kissed you. What you are feeling might be exacerbated by pregnancy, for sure, but it sounds like these are pre-existing problems.
I understand too why posters downthread spoke of the early child-rearing years being fallow - at that point you were not declaring the true nature of your problems and it is so true that even in the best marriages, intimacy can be subsumed by infant childcare.
This doesn't sound like your problem though Millie. In a few months time, this situation is going to get immeasurably worse because you will be subsumed with the new baby and managing the needs of your other child - and an already neglected marriage is hardly likely to get better against this backdrop.
If your friend or daughter was in this situation, what would you advise? If your son was in a relationship with a woman who felt the way you do, what would you advise?