Have I wronged the young man by ending the relationship with him out of a desire for repentance and to distance myself from sin?

One should not describe oneself as pious, for this is self-praise, which is forbidden, as Allah Almighty says: "So do not praise yourselves; He is most knowing of who is righteous" (Quran 53:32), and He Almighty says: "Have you not seen those who praise themselves? Rather, Allah praises whom He wills, and they will not be wronged, [even as much as] a thread" (Quran 4:49). It is obligatory to sever the forbidden relationship with the non-mahram young man, for friendship between non-mahram genders is a door to evil and corruption. Whoever is sincere in marriage should approach homes through their [proper] doors.