What you're going through is normal. That's why they call it the roller coaster. If there's one suggestion I would make is that you continue to get your self esteem stronger to prove to yourself that you do not need to depend on someone else for your own happiness.
I personally would not throw yourself into just business because you're afraid of this happening again. Get rid of the fear. Don't replace the fear with anger though. That's even worse. At the end of the day she is still the mother of your S and D and she will influence them as much as you will. There is going to have to be a level of respect between the two of you so that your kids turn out alright.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.