Hello Hanging and welcome to PC!
There is one statement in your post that had red flags flying high: "with an otherwise perfect husband..." First of all, as you well know, marriage is difficult, messy, and stressful. So if that comment was literal, then there is something else going on that you're not seeing.
But I'll give you my perspective as a wife who looked over at her husband one day and said "enough, why should I have to deal with this another day?!?" I did not think I would ever be in love with him again. In fact at the time, I could not remember what I was attracted to in the first place. I was bitter and angry. I'm not proud of this but I became a world class bee with an itch. The more I dished out, the more he took and that made me respect him even less.
Our marriage such as it was had to end. We separated. And truth be told during those 18 months my life was just as I wanted it. Things were how I wanted them to be; everything was neat and orderly and ever so peaceful, because in my mind he was the route cause of all that was negative in my life. My husband's issue is that he is bad with money. He's exceptionally intelligent but you put a $ and decimal point in those numbers and somehow he can't do basic math.
Reconciliation was never an option in my mind. I had my fill and I was finished. He was also very hands on with the kids and cooking and cleaning. While we were separated, he continued to make our children his #1 priority.
I began a "serious" relationship with literally the first man that made me laugh. He turned out to be the biggest horse's @ss that I'd ever met. After that, I tried going out for coffee a couple of times, but no one measured up. I was going to do it right this time, I was not going to settle. He also did some soul searching and realized that he was entitled to be loved and respected for who he was as a person.
Eventually we became friends again; and we started talking about topics that had nothing to do with the children. As it happens, I liked who he turned out to be. His version of the story is that he was always waiting for me to come to my senses, but I grew a lot during that time as well. As a single mother of four children you have to put things in perspective.
We really needed that time apart. I had to learn to let go of the little things and communicate when things were not going well. (I'd been the "you should know what you did wrong, if I have to spell it out for you then you don't know me at all type".) HE had to learn to make his needs known. That by pretending my behavior didn't bother him was making the situation worse instead of better. We decided to give it "one more shot" with the agreement that we'd put 100% in, but if it didn't work out we'd get a divorce because the yoyo thing was not for me.
That was 18 years ago. Now when things get rough, and they have over those 18 years, I can look at the situation and ask myself if this is important or am I letting those little life annoyances cloud my judgment. A friend from HS once asked me how things were going with hubby and I. The honest answer was/is that some days I love him so much it's hard to breath and other days I'd just as soon kill him as look at him. The love days far out number the kill days

.
We needed that separation so that I could learn that new isn't better or even easier. It's just new baggage that I would have to deal with.
Sorry for the book, but what I would suggest is to take some time and ask yourself what you want out of life (regardless of your marital status). Demand them. You deserve them. Do not settle.