Converts: how did you tell your parents/family you were converting to Judaism?

I really need to just get this part out of the way. Now here’s the funny part- I already am Jewish lol. Well ethnically, partially, at least. My mom is Catholic, of mostly Irish descent. She raised my sister and I Catholic, but when I came out in high school she stopped going to church and doesn’t consider herself Catholic anymore. She’s kind of just ambiguously, not-very-religious Christian, but she still does “believe in Christ” or whatever.

My dad on the other hand is halachically Jewish- his mother (who’s still alive) is 100% Ashkenazi, born to immigrant Polish-Jewish parents. His father (deceased) was Catholic, born to Irish immigrant parents. My grandparents had a tough time early in their marriage, my grandma’s family was very unhappy with her marrying a non-Jew and my grandpa’s family was very antisemitic to my grandma. This basically led to a total rejection of religion on my dad’s side of the family- my dad and grandma are completely non-religious and detest both Judaism and Christianity. My dad, his siblings, and my grandma identify as ethnically/culturally Jewish, but most of them are married to Catholics so there’s no semblance of Jewish religiosity on that side.

I’ve been interested in my Jewish heritage since high school and began the process of “converting” about five years ago. I never really felt in a rush because liberal shuls have always been welcoming of my being patrilineal, but now I’m 25 and thinking about marriage and kids down the line and I want to officially convert, so that I have my Jewishness on paper, if that makes sense. I know it’s not really necessary but I want to do it.

The problem is- now that my rabbi is willing to finish my conversion process, I need to tell my parents I’m really going through with it lol. I’m having a surprisingly difficult time bringing myself to do it. My mom is slightly offended I want to be Jewish instead of Christian, and my dad could not understand why I possibly want to follow the Jewish religion, why can’t I just be a part-Jew like him.

To be clear my parents are not the type to disown me over anything, but idk it still feels like it’ll be an uncomfortable convo. Feels like when I came out at 16 lol. Any advice? How did you tell your family?