I'm late thirties so would not have time on my side if I waited. Just out of interest, how did you children react when you did divorce as they were significantly older at this point?
Not yet divorced, but that will happen next year I think. The younger two are happy that I'm happier, they're pleased their DF and I are talking to each other rather than bickering and arguing, and I'm doing as much as I can to facilitate their relationships with their DF (so being the bigger person re bank holiday weekend visits etc).
But, as only DC3 is at home (with me) atm, the older DC have their own lives, and it's less of a big deal for them now I think. OTOH, I can see that they have perhaps not the healthiest relationships/responses to relationship conflicts, and that is a lot down to my modelling of relationships.
"Staying for the kids" is sometimes the easiest option (a lot of why I stayed was because of money being totally honest), but not to the detriment of your own mental (and in my case physical) health. My chronic pain is so much better now I'm not depressed and permanently stressed out, and being in less pain means I can do more exercise, which in turn reduces the pain levels.
I'm at a different life stage to you though, and once the DC are older and are pulling away from you generally, it's a bit easier to see through the fog, and properly look at what your life is like day to day, and think about what you might be able to do to improve it. For me, I had to get away, I didn't like where we lived, didn't feel I fitted in, and there wasn't the opportunity to do things I wanted to do (for eg, I'm planning a uni degree, which I couldn't have done where we lived, unless I went for the OU option). For you OP, it may be you can make changes and stay in your marriage and be happy.