People may comment that I sound selfish, but I'm engaging in reflection and self-awareness. Surely quality over depressed quantity is better for the children?
Reflection and self-awareness, always good. Facing up to your issues, also good.
It's really hard being a parent to young children sometimes. Lots of parents find it very tough, see themselves turn into husks of their former selves and wonder how much good they can be doing to these young minds if they feel crap about it all.
I don't think it is as black and white as 'quality over depressed quantity' when it comes to your role as your children's mother. This will affect them for the rest of their lives. Forge your path, do what makes you feel better about your career etc, but please don't underestimate the impact on your little children.
I know someone (much older than me) who did this when her children were 2 and 3 years old, years and years ago. She is still judged now, rightly or wrongly. Her sons have only just started to let her back into their lives (they are grown men now). She will never have a normal relationship with her grandchildren - her sons just don't trust her, knowing she is capable of walking away from them.
I can't fall into the 'hey, do what you feel is right' camp. I think the short and long term needs of your children should come first. That might fit with your plans, or it might not. Just don't assume phrases such as 'but that 20% is stellar' will cover it. You do sound somewhat detached, OP and I wonder if you should first seek more help, post-PND, before taking this step?
Personal happiness, and following one's own ideal is admirable, but now I'm a parent, those things come second to my children's happiness. Not everyone agrees, and that's fine.
Good luck OP.