You should keep seeing your therapist and stop talking/thinking about her. You're foolish to think you'll get over your ex (or get healthy), if you're still engaging with her. Painful longing for your ex is not love. It's merely a distorted definition of it you were forced to accept as a child. If you want a true barometer reading on how confident, secure, and healthy you are, honestly assess the person with whom you are trying to contact.
Easier said than did. If it were as easy as flipping and switch and saying "thoughts off" I wouldn't have to see a therapist in the first place.