Things will get better. Usually stress brings back the thoughts pattern. Are you stressed over something lately? Glad you are seeing a therapist again.
What you need is to learn how to deal with the thoughts when you have them. How to stop them in their tracks before they take on a life of their own. How to recognize the thought pattern and change it. Replace negative thoughts with positive ones. Were you learning this with your cognitive therapist?
Well it sounds like OCD to me but I'm not the expert. The only thing I'm expert at is having OCD.