Put your kids first...
Remember how precious they are and that your main responsibility on this earth is make sure they are protected and cared for until they are old enough to be on there own.
My opinion is this; no matter what "me generation" psychology you've heard, your kids come first and you second. That's it.
The child's pain
The number one victim (and I do mean victim) of divorce is children. They suffer both emotionally and socially. First their home life is split, they spend time with both sides of the family but never again together. On Christmas or any other holiday instead of seeing all their family together they usually only see one side. They usually have to endure someone maybe their own parent talking bad about the other. If they have split custody plan they have to constantly remember to bring their favorite toys back and forth, they have to remember their schools supplies, homework and books. That may seem trivial to an adult but it's not to a child.
If the parents can't communicate effectively then the child has to play "messenger" and gets put in the middle. When one parent is putting down the other the child can feel like they need to go along even if they love the other parent, this can cause great pain and anxiety for them.
My spouse is really screwed up, but my kids don't see it?
Kids love both of their parents even if one of the parents has serious problems and everybody else can see it, they wont. That's one of the toughest areas to deal with when you split. You may have an ex that's a drunk, a drug addict, abusive or any number of other problems that you can't fix but your children will love them any way. That's one of the beautiful things about kids, especially young ones, they love unconditionally.
What can I do for them?
If your in the situation demonstrated above your going to have a tough road. You have to do what ever is necessary to protect your children. You may be "screwed up" your self a but still better than the other side, it doesn't matter. What you have to keep in mind is that the goal is to raise your kids to be better than yourself, no matter how "perfect" you are it's still the goal. Your children should be taught to learn from your mistakes so they don't make the same one's, if at all possible.
I have full custody and my kids hate me...