Thanks, everyone, for your helpful and supportive responses. Let me try to address them…
Some suggested that I try to find more time for myself by setting firmer boundaries at work or going part time. I have considered this before now, but I think it’s not a realistic option. I am near the top of my profession in a highly-paid, high-prestige role (I’m not bragging, just setting context) and, understandably, people demand a lot of you in that role. I have to constantly demonstrate my worth and it is not possible to do that working two thirds of the hours of my peers. Of course, I could take a lesser role, but too much of my self esteem and identify is bound up in my work for me to be happy doing that. Also, ultimately, I enjoy my work and the financial independence that goes with it.
Others have suggested that I outsource more. I have felt some shame around outsourcing (don’t ask me why, I know it’s stupid), but your responses have helped me get a new perspective on this. I should and will get some more help e.g., I could get our nanny to buy food and clothes for our DCs (I do this currently, but she would do a better job of it than me), I could ask our cleaner to do more hours, and I can get some gardeners to take care of the garden (currently, I do it myself). I feel a bit silly for not having done this already, but I have always felt that I am being a bit of a princess by outsourcing and that everyone else seems to manage without doing it, so why can’t I. It’s clear to me from your responses that this isn’t the case, so thank you for that.
Lastly, the thorny issue of getting my DH to do more. I hear you on this and I know it’s something I need to tackle. His job is extremely stressful and demanding, far more so than mine, but I think he could be doing more at the margin. The problem is it’s hard to raise this with him without him getting defensive. I think, for now, I’ll take one thing at a time and prioritise getting more outsourced help. Then, in time, I can try to get DH more involved. If anyone has had success on that front, do tell me your secret!