Losing each other?

Hi, this is going to be quite a story I'm afraid ;-).
My husband and I have been together for 12 years and have a lovely little boy of 3. We had quite a bit of adjusting to do to being parents; suddenly you can't just do and leave whatever you want, and that took time and also caused quite a lot of arguments and irritations between us. In between, we bought an old house, demolished it, and rebuilt it mostly ourselves. My husband did this alongside his full-time job, and of course, family life just carried on. We worked incredibly hard, and after a year, we moved into our new house, but the expected relaxation and release never came. We had expected that once we were in our own home, we'd finally be in the right place, and it is our home, but somehow we can't enjoy it as much as we used to, sitting on the couch together, having time for each other, like old times. The hustle and bustle has taken a toll on my husband; he's very irritable, and even now, a year after the renovation, he's never been the same. It's also like we've lost each other; watching a movie together or going to bed early, there's hardly any action anymore. I've had a few conversations where I said things aren't going well and need to change, and we agree, but it just fizzles along. Our son is in the testing phase at his age, and especially with dad, he really gets under his skin. Somehow, my husband also can't really handle it with detours or in a good way without always getting into arguments; sometimes I feel like fatherhood is attacking him. He says he's very happy with our son, and we had the wish for a second child, but somewhere I feel like I shouldn't do it because I want it more than he does (in my feeling). We try to go out for days together regularly, but even then, it's just not there, which makes me anxious and sad because I just think, are we losing each other? My husband goes to see family more often alone; I give him that space hoping things will get better, but I also notice that with how things are going now, I actually prefer being alone with my son rather than together where it doesn't feel like it used to. I just don't know what to do. We've talked several times, and he certainly doesn't want to lose us, but I don't feel it. Then I wonder if he's just oversensitive, and I confront him with that, which he brushes off. What should I do? We've already had conversations, even very clear ones that things will blow up if we continue like this, but I just don't see it anymore. Is there anyone who has also felt like they lost their partner sometimes, and how did things get better again?