I'm tettering on the verge of the big "D", and I wondered, how do you know when it is finally time to throw in the towel?

I feel like I've wasted years of my life, but I don't think that is enough of a reason, considering we have children together. How do you know when you and your children would be better off in a divorced family, than living all together under one gloomy roof?

Thanks!!!
~K.