Sometimes people we love do bad things. And when it's not to us, it can cause a dialema where a. We don't want to belive it even when it appears to be true. And b. We think 'oh but they're lovely to me so maybe I can compartmentalise'. Seperate the him I love and the him who is cruel to others.
I'd imagine it's also extra hard when this person is someone you rely heavily on. Let alone, love dearly. So I absolutely have sympathy for you.
It doesn't mean you have to cut this person from your life entirely (though I suppose if a prison sentence happens then this may be somewhat mandatory I suppose). But this may be an opportunity to look for ways to become more self reliant. It may be hard at first, but anything new is. It sounds like you have a little time left to start putting plans in place for worst case scenario. Maybe he can help with that now too, help keep his mind off things.
But here's the thing, and I say this from a place of kindness but I know it might be hard to hear. Many abusers have friends and family who love them dearly. Fiercely even.
I look back in my own experiences, one particularly nasty person sticks in mind. I wish some of those people who tbh...knew these person was a monster ...even though he was not to them... had refused to be his rock whilst he hurt women, not just me, with impunity.
Now I don't blame anyone for another person's...evils... but... from another perspective I also look back in my life now and recognise that I had people close to me, people who I loved, who were cruel to others too. That was made excuses for them just as others did for those who wronged me. That I turned a blind eye.
And now, well now I don't. Now I step away from people who are... lacking in moral fibre. Sometimes it hurts. But I don't wish to associate with people who hurt people. And I firmly believe that if we don't stand for something, then we stand for nothing.
I'm sorry that you may experience loss as a result of your brothers actions. That it will make life harder for you. You don't deserve the consequences for his evils. But perhaps this in an opportunity for you to step back and reassess who genuinely I'd healthy to have in your life. And who you're actually just keeping in it because of fear. Or perhaps, who is truly worthy of our love.
Be kind to yourself at least,moving forwards.
Start planning for future difficulties now.