What is the ruling on a young man ending an engagement relationship after performing Istikhara and feeling uneasy and lacking emotional closeness, and what should he do regarding the girl's statement to him: "You are not a man"?

One must repent from emotional relationships and forbidden conversations, as the desire for marriage does not justify them. Matters of marriage and engagement require deliberation and not haste, and dissolving an engagement is disliked without a valid reason due to the negative consequences it entails. If the girl is religious and of good character, then consider marrying her and seek Allah's guidance through Istikhara.