If I were you, I wouldn't do anything about it. I wouldn't even get mad about it. If anything, continue to make positive change in your life and update your social media periodically to give her a nice good look about how you're handling the breakup--No big deal.

Don't give her the satisfaction of feeling like she made the right decision (ie depressing posts/pictures, angry rants, etc). She doesn't want to see you happy. She doesn't want to see positive change. She needs you to be weak to make herself feel better.

Oddly enough, people generally want you this way too. Nobody likes seeing someone take control of their life and turn a bad situation into a great one for themselves. Her ending things with you was meant for a better her, not you.

Dummie.