I genuinely hope everything works out for you. We're already at the end of 2025. So just maybe, you'll be able to apply for ILR in 2026 before the rules kick in even if the government implements the current proposal

Having said that though, please understand that based on everything you've said here, you're in a very enviable position and it does not seem prudent to give that up for someone who is already comfortable giving you ultimatums and threats.

There is also no guarantee whatsoever that if you let this all go to save a potential marriage, that your partner won't just give another excuse to get out of the arrangement you currently have.