My brother left Islam and I need strength

Assalamu alaikum everyone. Today I learned my brother has become a Christian. I’m writing this with a heavy heart, just using a temporary account because it’s hard to share. I keep telling myself to have sabr, but honestly it feels like my heart is shattering into pieces. He got caught up in strange conspiracies, and I think that led him to Christianity. For a whole year he pretended to pray and act Muslim, but now it all came out. He says our faith is false and repeats awful lies about Islam. He wants to debate us, but really it’s just to twist our words and preach at us. The things he says are so distorted-it’s frightening to hear. My parents are devastated; they look like they’ve lost their soul. My brother is barely an adult, and even though he’s moving out, I can see he doesn’t really want to. He had doubts but never talked to us or the imam. Instead he turned to those conspiracy channels he trusted, and they poisoned his mind. Once those ideas take root, it’s so hard to pull them out. Deep down I know time heals, and he needs to walk his own path. We can’t force him back-we can only pray that Allah guides him. I can’t hate him or be cruel, no matter what. Every time I remember, I picture my little brother who I grew up loving, and my head spins. Any advice or du’as would mean so much, but just reading this is a kindness. I’m trying to trust that everything will be okay. Allah doesn’t burden a soul beyond what it can bear. How can I reach him when he won’t listen? How do I stay brave?