NTA - I'm really shocked by the lack of empathy here. I would guess that most people that have commented that you're the asshole have never dealt with abusive family members or homes.

The fact is that if you had left your sister there, her life would have been at risk. She would have been in danger if you left and your parents threw her out of the house without any of her things, her phone, etc. What if you had left and your parents moved your sister and forced her into conversion therapy. What if they started to physically abuse her after you left. What if you left and your sister saw no other option but to kill herself.

I don't think people here are understand how truly vulnerable your sister was to be outed to verbally abusive, homophobic parents.

It's totally valid that your partner is bummed he's losing his space. It's okay that he wished he would have gotten a heads up. But him being so upset to the degree that you now feel guilty and feel like you shouldn't have acted as quickly as you did, is pretty selfish if him.

By acting as quickly as you did, you very well may have saved your life.