My OH did this after the birth of our daughter, said the same thing, not enough sex/cuddles etc. We were awaiting our wedding as well, to follow a few months after.
It was a devastating blow. I wasnt sure I could ever forgive him.
But...
Sunday we celebrated our 6th wedding anniversary. I'm not saying you should go out and immediately forgive him and put things right - i know it doesnt work like that. But it needn't be that everything ends permanently. Its easy to give that advice, like so many ladies here have, but the basis of the relationship before should be taken into account.
of course, if your OH was a dick beforehand, then fair enough, leaving him could well be the best course of action. But if everything has been fine beforehand, and he's not done anything like this before...then perhaps more thought - once some of the hurt and anger has subsided - should be given. After a while, when i could bear to stand OH for more than 5 minutes, we talked, and had counselling, and whilst it was him that had wronged, we both aired issues, and slowly, we worked through, and now our relationship is better for it. But again, thats us, it might be different between you two.
Hope you make the best decision for you and your girl x