Hi OP, to answer your initial question - yes, I struggle with similar guilt all the time! But like pp I've realised it's because I don't feel like I'm doing anything to change the world ... I used to feel guilty about my individual choices and that I should make different ones if they didn't fit with how I thought society should be.
I also - like you seem to, and please tell me if I'm wrong - saw gender (the social construction of what a woman is) as the important bit, as all the 'limitations' and issues in my own life seemed to be based on gender rather than sex. How I dressed, beauty ideals, women not allowed to be 'bossy' etc etc.
Then I got pregnant and my friends got pregnant and we had children and that's when I realised the biggest problems I faced were because of my sex. I had a job offer withdrawn because I was pregnant, a friend's promotion was given to someone else when she told her boss she was pregnant, another friend is currently suing her employee for maternity discrimination. The first two of those in a supposed 'woke' and progressive industry. It was me that didn't go out for several months because my breastfed baby wouldn't take a bottle, it was me that took a full year's maternity because even though my husband wanted to take 6 months he would only get statutory pay for anything beyond two weeks. It is me that has to give up years of a career to be able to have children and also facilitate my husband's job ...
And of course this isn't even getting into what vulnerable women all over the world experience because of their sex (child marriage, period huts etc)
I now see the importance of feminism as challenging the existing power structure to improve women's lot and position (including valuing domestic work and childcare). And while our family's choice for me to be a SAHM at the moment isn't the 'ideal' way to challenge power structures,sacrificing the best option in our circumstances wouldn't help other women out either!
Basically I perceive my choices as an individual re how I live my life matter much less than any action I could take to challenge the existing male-centred power structure. Be that writing to MPs, supporting domestic violence charities etc. As pp have said, I now view 'women' as a class and feminism as challenging the power structure to in turn change things for individual women. I don't believe that I as an individual can make every choice a 'feminist' one, and that indeed the concept is a bit meaningless when applied to the individual.
That's my journey! Sorry if it was too long. I've enjoyed reading your posts.