I was a similar age as you too at the time
it's a difficult one and I do spend a fair bit of my time thinking about it and I think there are pros and cons
the biggest thing for me is the kids - I think waiting till they were 18 would have been more sensible and less disruptive. My son had to start secondary school, get used to 2 houses etc.
I don't think you should settle for something that makes you unhappy but there also must have been some reason you married him - can you think back to what that was?
I think for me the kindness and shared experiences of having the kids should have been a larger draw than it was for me. Ultimately, only the two of you will ever know your kids the way you do. You will be their main advocates. When something goes wrong with the dcs at school, it will always be dh you want to turn to.
It is also very painful waving the kids goodbye when they go off to see your ex - and bear in mind nowadays, shared care is much more common so you may find it's not every other weekend but a lot more often that you don't see them.
If I could do it all again, I would try everything before divorce. I would do joint counselling, I would do trial separation. Like you, I just skipped those steps and I shouldn't have done. Whatever is wrong, make sure you have done everything you can to save it before giving up on it, especially if he is a kind man and loves you and the dc. If after that, you're convinced it won't work, at least then you'll know in a few years time that you did everything you could.