I'm in a slightly different situation, but thought perhaps I could offer something.
I married my first DH when I was 18 (yes, much too young), and the sex was great. It was an ok marriage. We had two great kids, both worked hard and built a home (as you do).
But, when we got into our 30's, 1st DH decided he didn't want sex anymore. He wouldn't discuss it, just said he couldn't be bothered etc., There was no physical problem or anything, to be clear.
Along with no sex went no affection - absolutely nothing. It's soul destroying to feel so unwanted and undesirable.
The years rolled on, because I was not one to go out and have an affair, but I was deeply unhappy. I was just a housekeeper.
When I was 45 I (by total fluke), started chatting, on a money saving forum, to someone, for some laughs, and it later turned out that was having the same sort of issue with his wife.
We were online friends, then we met, the feelings grew, and the inevitable happened. It wasn't just about the sex - it was more about feeling loved, desired and wanted. Neither of us were up to swinging from the chandeliers any more, but we fulfilled each other needs with love.
Finally, we ended up moving in together. It caused uproar, I'm not proud of it, but I regret nothing.
We married, we had over 20 years of love and laughter. Even when his health declined and the sex became impossible, we kept the affection, cuddles, and love. That never waned.
He died earlier this year, and obviously I'm decimated.
But, this isn't about me - I just came on to say what I think. We all need love and affection. We need to feel loved, valued and desired.
So, I'd grab happiness where you can. However you can.
Its a lonely place, in a marriage, to feel unwanted. It's deeply unfair for one person to just withdraw all affection.
Best wishes to all.