I (21M) got cheated on by my (20F) girlfriend

A few days ago i had posted about my relationship events with her. And finally we broke up now just now. We were in a cafe together suddenly while taking pictures there was a notification saying when are you coming back i miss you. I asked her and it was that damn cousin of hers. They chatted in whatsapp the only thing I didn’t have. She said you deserve someone better your too clingy. That broke me i told her to get on my bike. Dropped her home and told her its over. Before she could say something i just went home. On my way i weeped like a child even while writing this im crying.