Painful feelings are mostly the result of the meaning we assign to events, not the events themselves. "She left me & that means I am this that and the other and am doomed to be lonely forever". The pain of having to re-adjust to an existence temporarily less joyful is much smaller.
We can choose what meaning we attach to events, even though it takes time and effort to learn to.
Rationalizing and self-deception is not necessary. You feel the pain either way.
How many people have said, and suffered the pain for it, that they will never love again after a breakup? Just about everyone.
How many actually never loved again? It would be a rare exception.
You are feeling the pain, yes. Weirdly though, the self-deception is what brings the pain. Why that is so would be a very interesting topic.
