What is the meaning of the heart's attachment to a person not disappearing after repeatedly performing the Istikhara prayer with the intention of knowing whether it is good or bad, especially with a desire for the relationship to continue?

Istikharah (prayer for guidance) is performed for permissible matters. As for an unlawful relationship between a young man and a young woman, Istikharah is not legislated for it. Rather, it is obligatory to sever it and repent from it. If the young man repents and becomes righteous, it is permissible to pray for the facilitation of marriage to him. If he proposes, then Istikharah is legislated. It is permissible for a woman to offer herself in marriage to a righteous man, while observing the Sharia guidelines. If the marriage is facilitated, then it is well and good; otherwise, it is obligatory to completely sever the relationship and seek what is better from Allah.