So over the last month or so tension with my father has built up quite a bit. Context is that he is a strong believer in god (through Reform Judaism), and I'm not. He's generally a very open minded person who is cool with people having whatever beliefs they want and having whatever sexual orientation/gender identity they have... so long as they're not his own children.
Sucks for me, being asexual and not believing in god or having any desire to participate in religious services, even on the 'super important' high holidays where every jewish person, regardless of level of belief, supposedly attends a synagogue service.
I'd like to preface this all with the fact that I value my family, and even if we have our differences, my father is an intelligent person who is interesting to have around, and we otherwise have a good relationship that I want to maintain.
Now onto the main content. A little while ago, as the High Holidays were approaching, I informed him that I didn't want to go sit in a room absolutely full of people, not eat for the day, and sit in a room of people praying to whatever they believe in, or praying to whatever they believe they believe in. Not even to keep things smooth with my father, because it's boring and inauthentic for me. I have to have enough of a mask on in day to day life that I don't want to add yet another layer to that (and be super bored and uncomfortable for a good half of a day in a place where it would be considered disrespectful to bring a book and read).
He got very upset about the fact that I wouldn't go, and told me how disappointed, upset and angry he was, and proceeded to ask me where he as a parent had failed such that I became like I am, rather than be a good Jew like him. He also asserted that as a parent it was his right to expect continuity of his beliefs in his children, which is why he is so close-minded with his kids but so open-minded with literally anyone else. Less than a week later he joked about saying that when I moved back to my home city (changing universities), I could find somewhere else to stay. For a time I was worried that this would come along with a financial cut-off, which would be rather problematic for me but overall could be dealt with if it actually happened, but I don't think it will come to that.
He has said that somewhat seriously in the past though, when I said a few years ago that I don't consider myself to be Jewish if being Jewish means I have to believe in god and pray and all that jazz, and he said if I didn't consider myself Jewish I should immediately pack my bags and get out. That was kind of real.
Right now, and not due to that emotional manipulation, I do consider myself Jewish and a part of the Jewish community, but only through cultural ties and not religious ties. And I don't want to be restrained by anyone who wants to assert that this is 'not Jewish'.
So my advice request: Has anyone dealt with similar-ish experiences and has advice on how to reconcile this information? I would like to avoid being in any way cast out from my family or just from my father. It's probably worth mentioning that if he did decide to cast me out, the whole rest of the family would probably side with me, and that would probably blow up the family altogether which is another unpreferred outcome.
So, any tips?