Living a life of worry and nervousness because you are concerned about what others think of you rather than knowing that only you can be in the best position to look after yourself.
Become successful. They say success is the best revenge for anyone. Let your ex know that you became successful without them and how worthless they were in your world after all.
The only person that can give you the fulfilled and interesting life you deserve is you, and no one else. And to tap into that you have to learn to please yourself first.