The kids still need lots of care (they are 5–9 years old), so finding time and motivation is still a challenge. For me the trick is to do training I really like. That helps so much with motivation. So, find something you like!
What I happen to like is bouldering and hiking. I have a fixed day of the week for bouldering, just after work, and I never miss it, because I know if I start skipping I might fall off my training habit.
Then the rest of the training is motivated by getting better at what I love. I do pull ups to better my climbing etc…
I will fight hard to keep at it through my 40s, because it is such a quality of life improvement. I also attribute the fact that I haven’t been really sick the last few years to my exercise.
The oldest go to bed later and later & I also like to hang out with my wife for a few hours each week... finding the energy and motivation for "me time" has been tough indeed. I should just do something I like, and stick with that on a regular schedule. It's as simple as what you write.
Go for it!
And try not to be in the majority group of gym goers who pay the membership without attending ;)
The nearest gym is truly the best gym for 90% of people, as everyone seems to look for excuses not to go. So just go, people there will not bite you or shame you.
Spotted an 18 year old the other day that hit a PR at 315lbs on bench. I bench 405lbs and at that exact moment I decided I have to hit 495lbs. 405 had been my goal for decades. I went from I've hit the most I will ever need to "the journey continues".
"people there will not bite you or shame you" I have found the gym to be filled with the most grim looking people that transform into the kindest, happiest people as soon as you say hello. No one is there to judge anyone. You are 100% right
But! There's no shame in napping mid-day, even more than once. Even in the office :)
Looking back at pictures from really not that long ago (less than 5 years) to before kids or the first year of the first kid and one of the overriding comments both me and wife have are "We look so young!". We have two aged 3-to-5, and its been hard but not that hard, especially now that there are no nappies/diapers and they sleep 10-11 hours straight overnight and we pay for gardeners, cleaners etc and pretty much do our usual 9-5 as we did before kids.
FWIW though, I would say that you don't need a gym membership. I try to run/jog/saunter a couple of times a week - its free and easy to do. Getting started is as easy as putting some shoes on and stepping out your door - no set up, no memberships, no travel to get to the place to do the running etc. You don't need to go buy special shoes or anything - just something vaguely appropriate will be fine to get started with for short distances and steady pace.
Its what your body has evolved to do, and I think there is a good mental-health aspect to just going out on your own and running and letting the mind wander. I personally don't especially "enjoy" running, and it is sometimes hard to persuade myself to actually go do it, but once I have started and I am 5-10 minutes in, it's quite nice.
Good luck
Now that they are older I have more free time. Once they get to the point where they can stay home alone things become much easier. For me that was around when they hit 10. I'm 46 now and in the best shape of my life. Keep pushing through, there is light at the end of the tunnel