What happens to single people who don't have sex?
They don't feel rejected night after night after night, by their loved one sleeping right next to them.
OP, I had 20 years (stupidly) of this. It will gradually crush you and can cause mental breakdown, depression, soul destroying, diminished self confidence, all sorts of problems.
It distorts your view of your own sexuality. I remember feeling surprised and confused if another man made a pass (even jokingly).
I had literally forgotten I was an attractive young woman.
The excuse to you at the moment is that he's heading towards middle age. In a year or so there'll be another excuse. Then another and another.
The sex will stretch to 3 months, then 6 and so on. We had one child, that's why I stuck it out.
I put tons of weight on from comfort eating, that was then used as another excuse "he didn't fancy it because I was too fat"
I had an affair in the final 2 years of my 20 year marriage. Satisfying and exciting but not much more.
I feel you should suggest sex counselling and /or a visit to GP. If he thinks enough of you, he will agree. Mine didn't and I finally left.
I later met my lovely dh and had two more children.
If you don't take this advice, at least remember my words as time passes and you will recognise them in yourself.
Please don't waste years of your life like I did.