What is the best thing to make an ex miss you and regret doing wrong things to you? Why do guys get angry when confronted?

I'm no perfect. We met at work and really grew fond of each other. It was more like a situationship not exactly like we dated. But things went downhill, we ended up hurting each other. I made him angry and he pushed me away. We don't talk to each other now. I deleted his contact and he did mine. We both had different career options so left the job not at the same time but eventually. The reason was I confronted him about our relationship but he got angry and was not accepting that he had feelings for me. What is he doing and why would he do that? I'm not wrong, I still believe I was right by expressing my feelings truly but he wasn't which made me really angry. I want to make him realise that what he had done was wrong by playing with my feelings which he never accepted. I later heard that he threw shade at me on his WhatsApp status also. This guy is a jerk. Please help me!
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6 mo
He was very competitive with me too during work days.
What is the best thing to make an ex miss you and regret doing wrong things to you? Why do guys get angry when confronted?
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