I think I made the wrong decision.
What kind of decision was it and how did you come to your decision?
I based it on probability.
You can't always make the right choice. Just because something is likely to happen, doesn't mean it's going to happen. Don't beat yourself up over the decision not going the way you wanted it to.
I can't help it.
Everyone makes mistakes! There's nothing wrong with having something go wrong. The important thing is to learn from your mistake and to not let it consume your life.