I hear you out. My marriage feels this way on and off and it's frustrating (this tells me that my husband and I haven't yet resolved many of our issues, but I hope it gets there).
I am glad that you can stay home with your kids, it's truly a wonderful thing to be able to do that in this day and age where many parents are having to work.
I, too, am a stay at home mom to two little ones. It does feel lonely when you're chasing after kids all day and making sure their needs are met while doing the household chores. Sometimes it feels impossible to get it all done. It does get lonely when the interaction you have all day barely goes beyond Paw Patrol and Sheriff Callie.
What I'm told helps is having some mom friends. Right now, many of my friends are still single without kids and they are friends I have had for a while. They don't seem to mind my kids or anything, but when I try to invite them over and my husband can't keep our 5 year old busy, she will interrupt every conversation and won't stop talking and consume all of the guests time, which annoys even me. Then she complains that she's "bored" when she is told to find something else to do. I would assume this is why my friends don't suggest hanging out while my husband is at work and they probably don't understand that I have to get them to the toilet or clean all the water they spilled on the kitchen floor and leaving them alone to go deal with something. Yes, it gets so lonely. Even if I did have more friends, I don't think they'd be stopping by that often.
Have you talked to your husband about how he feels about you and how you feel about him after the kids are in bed? This might give a lot more clarity. If he's the only one working a paying job (not saying stay at home mom isn't a job, but it definitely doesn't pay in Washington's) then he could be downright exhausted by the time he gets home. Kids wear you out and work wears him out and it can be a rough combination to even spend more than a few minutes a day together.
My husband has a lot of health struggles so he's not in the best of moods. When I met him he was the most positive person I met, trying to help me look on the bright side of things. Here, I am, looking a bit more on the bright side of things, but he has turned into what I used to be - the pessimist. It's an interesting flip, but it happened and I can't stand it. He's so negative a lot of the time and it makes it hard to keep up with my housework because it doesn't make me feel all that motivated.
The other day, the washer was half full and he said, "I'll run the load, it's just 'easier." Of course it's easier for the person that doesn't even help put the clothes away, right?! I don't feel that he respects me that much.
But, I definitely pray and hope that we can work it out. The last thing I would want is for it not to work out. We've been married this long and been through a lot, I'm sure we can find a way to pull through like we always have.
I have vented to people about marriage troubles before and I got burned pretty badly - long long story, but it didn't end up well at all. It was the roughest point in our marriage because these people were trying to get us to divorce in the end. So, I have great difficulty sharing marital issues with anybody.
You can try 7cups.com and get a free listener (note: not all of them are always helpful, don't feel bad going through listeners until you find a nice and helpful one) - they have therapists on the site, too, but they do charge money.