Avoiding Someone During Chabad

I am a Christian woman with Jewish ancestry on my father's side. He has started returning back to his faith including visiting the Synagogue and different events. He has talked to me about possible conversion and what not. I have always appreciated my background from a cultural standpoint and had been active during my college years. But I prefer being Christian in faith. This has been going on for a few months now.

Anyway, I used a popular dating app and stumbled upon a Jewish guy I liked. All went well as we shared similar goals and interests. However, it quickly took a dark turn when we both somehow dabbled in intense and taboo "religious play." I said and did things that were out of my character as I'm a virgin waiting till marriage. I declined going all the way and it ended pretty badly. Despite this I was still willing to help him with a very delicate surgery as he had asked me for help prior. A few days passed and I called the hospital to see if the surgery went well. When he picked up the phone, he had a cold and disgusted demeanor. Pretty much made me feel small, discarded and worthless. It was something I had never encountered before.

Anyway, I prayed to God and promised to never do anything like that ever again as I still feel hurt and guilty. The problem is that my dad really wants me to go to Shabbat dinners and Chabad in general but I am scared and mortified to find the guy there in the future. I am also scared of him telling others what we went through. I want no one to know the details as I am ashamed.

How should I navigate this in order to avoid him? I am scared of him telling the rabbi or my dad finding out. I feel like I should just not show my face at all anymore as I really don't want others to know what happened. What are your suggestions or how do you deal with people you've dated that no longer worked yet still have to face them in the synagogue or other events?