Your life sounds stressful and not very well balanced - work/life balance I mean, you seem to have all work, no play.
If you don't fancy anyone else and say your DH is a decent man, I would try my utmost to save your marriage. Yes, small dc and stress, full time jobs, sleep problems and household can take all your energy away. No wonder there is none left to maintain your relationship.
We started to go out every Saturday and Sunday for a couple of hours on our own, without any of the 3dc, to cafes, pubs, walks in the woods, anything really just being a couple. Luckily the youngest can be looked after by eldest, but even if not, we would have started hiring a babysitter.
Going out in the evenings is nice too, but I found it even more tiring the next day when my little one was small. The most important bit was starting to feel as a couple again, not just being mum and dad, cleaner, worker, cook, general dogsbody.
We have had times when I felt no desire at all. I think it's the body's way to conserve energy when you are already running on reserve.
A cleaner is a good idea, I've always had one when the dc were very small. Just to take the pressure of having to clean the bathrooms off me. Only 2 hours a week for bathrooms, hoovering everywhere and mopping made a huge difference for £20.
When I worked full time with 2 under 4 I also had an ironing service, one basket of stuff ironed a week (all work stuff) so I didn't have to worry about DH or me not having anything to wear after a particularly awful night with the sleep-refusing toddler. Or having to yank the ironing board out in the morning.
Those years with little children are mostly about surviving with your sanity and relationship still intact. Whatever it takes imo. Don't let anyone guilt you, don't feel guilty yourself, stop putting pressure on yourself to do it all yourself.
I read a lot about the paradox of parenthood. How children are more or less seen as the ultimate thing to make humans happy, but in reality they are a shock to the system, an incredible challenge mixed with joy.
There are books about it, the one I liked best was written in my mother tongue, but there are English ones like "All joy and no fun - the paradox of modern parenthood" by Jennifer Senior. There are lots more books on this paradoxon.
Good luck OP. I'm a few years down the line, my youngst is almost 7, and my marriage survived, sometimes it was difficult, but I never felt it wasn't worth it.