Relationship Issue?

[RelationshipProblem]

Name changed for obvious reasons.
My partner and I have been together for 20+ years. We have two kids, one with SEN. My partner is the main breadwinner. We aren’t married because I have never been keen.
We generally get on well, share the same values and interests. He is very considerate and generally supportive. Though we do bicker. We don’t get to spend much quality time together.
Sex is becoming a massive issue. He wants it, I really don’t enjoy it. I could quite happily not have sex again. But, he is not unreasonable in his expectations. We have settled on once every few weeks. But I am finding it really difficult. Having sex doesn’t feel right for me. I am essentially ‘lying back and thinking of England’.
I don’t know what we can do about it, everything else is pretty good, but we are just totally mismatched in this area. I feel it would be devastating to our children for us to split up. I’m not even sure whether this would be possible financially, as we live in an expensive part of the UK.
I just don’t know what to do. I can’t envisage my partner ever being willing leave the family home. But at the same time, I just have a real block on sex, which I don’t think I can come back from. There’s just no sexual desire there for me and there probably hasn’t been for a long time.
Any ideas? Anyone been or going through similar?

We were in a very similar situation. It festerred for years, and has now lead to divorce.
We went through lots of counselling, but never really dealt with sex. Without it, the cracks just got bigger and the stuff that we should have been able to fix got worse.
My honest advice is see a sex therapist. Not just a relationship counsellor. Find someone who belongs to COSRT and who will be able to see you both together and seperately. Go into the sessions wanting to make things better, bot just for them to be better. And do it now, because the situation will not fix itself.
There are so many threads on MN like this and it breaks my heart, because so often it seems like people want to fix it, but are too scared because it's about S-E-X.
Good luck.

Thanks for your reply @Estherpologist. I appreciate your advice.
Sorry to hear about your divorce too.
Sex really is the crux of the issue. I'll give some serious thought to your idea about the sex therapist.

The problem is, you’re having sex that you don’t want and he wants more sex, it seems you’ve managed to compromise but it doesn’t sound sustainable.
Is there a reason why you don’t want sex?
Do you still fancy him?
The problem is, no one should feel like they have to have sex and it must not feel good for your DH knowing you don’t want sex.

I agree @SparklingStars10, really not good for either of us, and yes, it can't feel good for him, to not feel desired. Although he seems to have accepted that.

I don't think I do fancy him anymore, though I can see objectively that he's attractive.

Do you think because you don’t fancy him that could explain why you don’t want to be intimate with him?
Or do you have no sexual urges at all?