I recommend The Cut on YouTube for lots of good content. They have a series called Keep It 100, where they interview 100 people about a certain topic. This one happened to be about your worst breakup. Some are simple, some are complex, but they all teach us something about the human condition and the way love works...
I was on the receiving end of my worst breakup. It was New Year's Eve. I was in high school. I was dating a girl who I thought was a nice girl. We had been dating for a few months at this point. She invited me to a house party in our area, the house of a mutual friend. We're at the party for an hour or so, and then she disappears. 20 minutes or so go by and I start to wonder where she is, and start asking other people at the party if they had seen her. A few minutes later, a guy comes up to me asking if I had a condom. I put two and two together, and it turns out he was trying to f**k my "girlfriend."
I left her at the party and joined up with my friends. She called me shortly after midnight, crying and apologizing. I called her a horrible person and haven't spoken to her since. I realize now that it probably wasn't that bad of a breakup, since relationships in high school are pretty much bullsh*t anyway. Kuddos to you if you found your forever love in high school, but it's rare and ultimately limiting to your worldly experience in my opinion. But anyhow, good luck in your love life and relationships, and try not to f**k anyone over if you can help it.