I'm glad my experience has helped in some small way Cathy. It is very hard to leave a marriage, no matter how miserable you are, because it is something you invested hope, time and love into, and you have to let that go, and it hurts. Having said that, there is hope for a better life once it is done, and happiness either by yourself or with someone else, with whom you could potentially have that happy marriage you wanted.
I think Farfaraway is right, divorce will not scar your kids. What scars them is rage, resentment, arguments, and hurt. And sometimes we need to be a role model - when your kids are young adults, would you want them to feel they had no choice but to stay in a loveless relationship, or have the courage to go find their happiness?
People might judge, or decide it's your fault; but should you live a life of misery in fear of their casual thoughts and opinions? What will you wish you would have done 20 years from now, or when you're on your deathbed? Sometimes we need to let people have their opinions and not worry about them, even our families, and in return we live our lives that little bit more happily. And what have you got to be ashamed about? Stand tall, throw your head back, and declare that you are a strong woman who deserves to be happy, and you will not put up with a life of misery, and if they were really your friend or family, why would they expect you to.
If you do decide to leave, be smart and go see a lawyer and a financial advisor first. Work out budgets, money, child support, care arrangements, accommodation. I would also suggest a counsellor to work through emotional issues you will experience, it is good to work through them with a professional. Line your ducks up first, and it will benefit you and your children later on. You might not be able to afford as much, but we get too caught up in possessions anyway, love and happiness is what matters.
I hope you find your happiness, no matter what it looks like!