Feeling Low

I woke up this morning from a nightmare. Have you ever woken up angry, sad, depressed? It has to be the worst way to start a day. Today, I woke up depressed. Feeling hopeless. Like there's nothing I can do even if I wanted to do something. My nightmare involved my brother. My brother and I haven't got along for a while now. He's so full of hate and anger that it's pretty much impossible to talk to him. Usually, any conversation ends up turning into some sort of attack against me. It's like he purposely wants me to be mad. Maybe he does.
One of my sisters pointed out to me that he is probably depressed, and I think she's right. Some people deal with depression by staying in bed all day and not eating. My brother deals with it by drinking, hanging out with the wrong people, insulting others, only leaving the house to buy cigarettes, among other things. I know he can't be happy with the life he has. And I would love to reach out to him, to let him know that I care about him, and that life can be better. But he's so caustic, so volatile that I know if I ever said these things to him, he would pretend not to care and would probably insult me in some way. I've tried before. I've told my mom that he needs counseling because he's heading down a dark path, and he needs to turn back before it's too late. Of course, she shut that down. "Why don't YOU ask him, then?" she shouted at me. My parents are both in denial about his situation, and my parents never were the types to like any sort of outside involvement, even though I know counseling/therapy/etc. would benefit each and every one of us.
I've told people about my brother before. "He's going through a phase," they tell me. I know they mean the best. I've been thinking that for a couple of years now, and I'm not convinced. As much as I want to believe, yes, it's a phase, he'll realize how much pain he's causing to himself and his family, a part of me is scared that it isn't. This mean, hateful, sad side is here to stay. And it'll only get worse. Nobody I've talked to seems to quite understand what my family is going through (although they don't know every little story about my family and I). I know my friends mean the best with their advice, but I feel like they can't understand. How can they, anyway? They didn't grow up with these people--I did.
I feel stuck about the whole situation. Is it a phase? Do I just sit it out? I'm scared he's going to permanently hurt himself. I wish I could convince my family that he needs someone to talk to. He doesn't want to listen to his family, and I don't think any of his friends are good people to talk to--I doubt he'd ever talk to his friends about serious stuff.
I just want my brother back.