SchrodingersCat, I agree that mono people face the same issue or comparing to other lovers that their current partner has had. I also agree that the idea that she "is still with me" is helpful. Also, she started dating me after already dating him, so I must have been enticing in some way. That concept does help me a little.
Still, I'm not cured. For example, I believe that feeling disapointed about being less articulate is justifiable. Also, feeling insecure about being less entertaining is justifiable in my eyes.