NoMoreFor just to add. if you stay, and pretend, to 'make everyone else happy', it won't work in the long run. Your unhappiness will seep out, your children (and DH) will feel it, it will be everywhere.
My mum stayed in an unhappy marriage for a very long time. For different reasons, she was afraid to leave (cares a lot what other people think, saw it as failure) and, also, she wanted to work and change things, she wanted my Dad to love her differently / better. He is an emotionally closed person who burried himself in his work and cared for, and even noticed her, less and less as time went on.
Through my teenage years the dynamics between them got more and more obvious, and made home life more and more uncomfortable and unhappy. I couldn't wait to leave home, which I did at 18, and spent as little time as possible there from then on.
You don't say how old your children are. Possibly divorce is harder on young children. Possibly. So you might consider giving it a little more time until you think they are better able to cope. But the older they get, the more they will feel and see the dynamic of your unhappy relationship. And now you have worked out what is really going on, it will be harder, over time impossible, to hide. Kids know when something is wrong. And it is unsettling for them to know that and be told that everything is ok when they sense that it isn't.
I think it is possible to leave and have that be the best outcome for everyone, if, as others have said, you work hard to keep it civil, work out custody, visiting and access that works best for everyone. If you accept their upset and anger. And, crucially, if you take responsibility for your choices and your feelings and seek the support you will need from your friends, adult family and or a counsellor, not your children.
My mum did eventually leave when I was in my 20s. She lent on me and my siblings a lot then, probably too much, for emotional support - she seeking for us to parent her. She does not truly take responsibility for her own choices (e.g. she has told me many times that she would have left much earlier but 'couldn't because she had young children' obviously the implication here is it is our fault she spent so long in an unhappy marriage. This is untrue. She didn't leave because she wasn't ready to, but giving an external reason is a great way to avoid taking responsibility for that choice).
She is also a walking example of the maxim 'women in unhappy marriages fixate on their children.' Even as my siblings and i became adults she was overly involved and invested in our lives as some kind of 'compensation' for her 'sacrifice'.
Her staying did not make us, her children, 'happy'. On the contrary I have spent a while as an adult working through the legacy of growing up in the middle of an unhappy relationship and redrawing some healthier boundaries between the two of us.