I think life is dynamic, relationship is dynamic and subjectivity is dynamic. A lot of people in couples drift apart when they have such differing lifestyles as full employment for one and SAH for the other. You wouldn't think of it now, it happens slowly and until the time ppl realise they have travelled completely different routes it can go unnoticed. Your 5 months are just euphoria, but what happens in years, what happens with your mind, with your self, with your DH attitude, with your relationship, is impossible to predict now.
I would personally never leave my job, I love it to pieces and I cannot imagine how on earth I can live being confined to the house. Networks of friends and other mums, parks and everything is nice, but not ALL the time. There is realisation, professional realisation, growth as an individual, which IMHO, is not achievable at home. There is a lack of mechanisms to be pushed in that manner at home. Because it (self-development) not only comes from inside, it's a process consisting of multiple things, some inside, some outside, some born in this interaction.
When your child is 5 months, it still sleeps a lot. Imagine, having no time absolutely, in 6 months time and with more DC, for yourself. Nearly never. Read a book? Forget it. You turn into a serving machine, caring system, nursing, feeding, doing that, or that, whether you want it or not, always, no way out, no space for your brain to do smth different. For me, this is misery.
I am so grateful to our greatgrandmothers fighting for us going to university, having jobs, leaving the tyranny of the domesticity. Domestic is so nice, relaxing, but it can really strangle if you're not careful. Things turning up strangled in the end can be vary varied for different individuals, but something suffocates for sure in this lovely embrace.