I lowered my bar for "making time for myself" and can generally manage it by restructuring my day slightly. Possibly none of what I did will help or work in your life, but I'll tell you in case it gives you ideas. I work and my husband is home with the kids, so I will admit to having some "kid free" time built in, but my work is in early childhood and family mental health, so except for the occasional "paperwork day," it's not like I am sitting in a quiet office filing or anything... but anyway, I will be the first to admit that I have daily kid-free opportunities, but when I am not working I am 110% "on" in order to give my stay-at-home husband some relief and to manage the logistics for parenting 4 kids. I also single-parent fairly frequently when my husband travels.
Anyway... I looked at my day and decided what the worst parts of it were. For me the absolute worst was the morning rush (getting breakfast for everyone but myself, getting lunches packed, kids dressed, diapers changed, dishes dealt with, laundry started). I didn't try to find time to sit quietly and sip coffee while reading the paper (which is what "they" seem to expect me to accomplish), but I decided I REALLY need to eat breakfast, preferably sitting at the table, and to make coffee to take in the car with me. In order to make that possible, I needed to eliminate some things from my morning "to do" list and/or create more time in the morning. So I started making lunches the night before (either while I am cleaning up dinner and/or after the kids are in bed) and packing my work bag. Then I set my alarm for 10 minutes earlier (when I am single-parenting I set it for 30 minutes earlier in an attempt to get up before any of the kids). I taught my older kids to get their own breakfast and enlisted them to get breakfast for the littler ones. I have considered re-arranging the cabinets so the kids can more easily reach the things they need, but I haven't managed that yet-- for now I make sure the stool is out or might leave bowls out on the counter... I'm still working on that one. I also have been working on requiring the older things to do things for themselves as is developmentally appropriate-- I really did NOT need to be getting their breakfast, picking out their clothes, finding their socks... but in the rush it seems easier to just do it than to wait for them to figure it out while whining and getting distracted and making us all late. I tend to force them to practice self-sufficiency when it isn't important (for example, I don't get up to get them a clean fork at dinner, I don't go track down their water bottle before bed or their library book that they want to read)... slowly it is getting easier in the mornings when I refuse to go find a favorite pair of jeans and they can actually deal with that crisis themselves.
Anyway, I don't know if my rambling is helpful... but my point is that I will NEVER, unless I start getting up at 4am, be able to sit and have a leisurely breakfast and coffee while reading a novel in the morning sun. But for now it is enough to free up the extra 5 minutes I need to eat my own breakfast uninterrupted. I've done the same thing for bedtime and in the afterschool rush between school pick-up and afterschool activities. It doesn't always work, and I frequently have to realize when things aren't working again and make some other adjustments. And it has taken an initial investment of teaching the kids how to do things, and/or making visual aids (like the one in their bedroom with a picture of pajamas, toothbrush, water bottle, and books that reminds them the 4 things they are responsible for in the bedtime routine)... but in the end the investment pays off, and it has a ripple effect-- once I raised the bar for the kids doing things on their own, there are more things they automatically do on their own without first asking me to do it for them, and it is a smaller step to enlist their help with the littler ones (for example, the older two can put the appropriate amount of toothpaste on the littlest one's toothpaste for him, or can help him go pick out pajamas).
I still haven't figured out how anyone gets a "girl's night out," takes a class, dedicates hours a week to crafting or gardening, goes on a date with their spouse or whatever... But for now I'll satisfy myself with meeting my basic needs on a more regular basis.
Sorry this was a bit rambly... I'm typing this while taking a break from catching up on paperwork for my day job while supervising the toddler and helping my 1st grader with homework in the lobby of the dance studio where my 5-year-old is in class.... HOpefully some of it was coherent!