Betrayal

So, yesterday I discovered something bad, really bad and now I have to make a decision which will define the rest of my life and my children's lives, so the question is this, do you do what is best for the children or what is best for yourself?

If you have the answer to this, please let me know, because right now I am struggling to decide. Part of me has already made the decision but am too scared to go through with it, does that make me pathetic or a good mother?