OP, it sounds like your current role is not making you happy, it is horrible doing a full time role that you would rather not be doing, it is horrible. So I hope you find something that makes you happy, life's too short.
As others have said, not all, but the majority of people can't have it all at the same time, they have had to sacrifice something along the way, and those sacrifices can change along the way.
If you are in this majority, It's just what your willing or able to sacrifice.
It's not that you can't juggle like others can, so don't put this on you, it think it can be really tough being a full time working mum. You need a great support network that you can rely on, in a-lot of cases that's for childcare, someone great who you can rely on to look after your child while you work (nursery, childminder, clubs, activities) and a husband/partner who does what he should at home. How does he feel about the SAH option or swapping jobs ?
I think in a lot of industries it can be hard to get back in at the top once you step out of that for a few years, so if you chose to work less in a different industry, you would have to do so knowing you may not be able to get back in.
Although I think many middle/lower management roles are easier to get back into, if you keep up your industry knowledge and training, so it would depend on what role you are looking to get back into if you don't like senior management anyway.
Ultimately The bottom line is you need to do what works for you and your family and feel no guilt. If you need to reduce your hours for a bit and you can afford to, your partner is happy for you do so, providing you are aware of all the downfalls to that, do it.
I never regretted stepping away from a higher paid role, I didn't miss the mental load of taking your job home with me and it being a bit all consuming, but that was my role I'm not sure if yours feel like that for you. We could afford for me to do that, I don't regret it at all.
But, everyone is different, so weigh up all pros and cons, if your worst case scenario for your situation appeared, would you still be happy.