I [27m] had plans to propose to my gf [25m] this year, but her parents are now making me question if I should go through with this...

Been dating my gf for a few years and I finally got to meet her parents recently. I know, it took a while for me to meet them because she comes from an extremely conservative/helicopter parents who are religious fanatics. I recently met them and now they want me to convert to their religion ( we are both Christians but they want to convert me to their denomination) However I am heavily against this, and especially forcing religion on someone is something I cannot come to even see eye to eye with.
I told them I will "think" about it and sort of just let the situation dissipate. Now, they're really antagonizing my gf for dating someone who is not of their same denomination. Their constantly egging her on about her choice and its pissing me off to the point where I don't know if I should even propose until the situation is figured out. She has always lived under their roof, and essentially has been sheltered for most of her life. She doesn't really talk back or stand her grounds to them so it makes everything much more difficult. I really don't know what to do..
So I guess my question is, which option makes the most sense?

1. Stay with the plan, propose and just ignore the parents?
2. Delay proposal till she figures out how to deal with parents?
3. Break up temporarily to figure out things?
4. End things cleanly (really debating this choice here, because I cannot deal with toxic/interfering parents who will cause trouble down the line in the marriage, as I've known of couples with horrible in laws that have lead to divorces)

TLDR: Parents of GF are religious fanatics who will not approve of me unless I convert to their religion. I am heavily against this and cannot continue unless gf deals with them.


Source.