The best thing you can do for your children is to bring them to Jesus every day in prayer. HE is the one who will father and mother them in the best way. Trust that, and then just give what you can.
You will make mistakes, but at the same time, they will learn how to deal with the unfairness of life, and learn to cope. As long as you love them, and show that love in nurturing ways like listening to them, encouraging them and affirming their worth, all else is really secondary.
Pray also for the Lord to give you a heart that can truly love them unconditionally.