He left, and I didn't see it coming

My "boyfriend's" sister really despise me and I have no idea why. I've been with my boyfriend for just over a year now. Whenever I am amongst his family or at his house, his sister would pass really awful comments which would be directed at me. I tried ignoring it, didn't allow it to get to me. I spoke to my boyfriend, but he seemed to not take any of my concerns to heart and it has deeply affected me. Yet, I overlooked it, just to maintain the peace.

A few days ago another incident accorded. This time, I was fed up of it. I told my boyfriend just how much it hurts me that he doesn't speak up against his sister, and that he's been allowing her to ill-treat and disrespect me because he doesn't stand up for me which basically shows them, they're allowed to treat me whichever way.

Instead of having him listening and trying to understand my feelings, he disrespected me. Gave me the silent treatment and basically ghosted me. It's affecting me so much. Just last night, I saw I've been blocked on literally everything.

How do one overcome that? I'm still in complete shock. I cannot wrap my head around it. He just, left. No indication. No warning sign. I didn't see it coming. My soul feels, broken. I'm struggling to digest it.