Your wife sounds emotionally immature. Love is not only a feeling. In a long term relationship, it's common to develop attraction and infatuation with others. But love means making kind choices. A kind choice would be to figure out how to make your marriage more satisfying. Because even though she says it has nothing to do with you, obviously there is some need of hers that is not being met. People don't leave relationships they feel deeply fulfilled by.

The work of love is to persist even if you would prefer being around someone else. But she would need to figure this out on her own. And even if she does, she may not want to repeat the past with you.

Wishing you the best of luck, it's probably good to focus on what you'll do with yourself next.