Serious sibling squabble

About a year ago I moved in with my big brother and his girlfriend. Things were great for a while but now, not so much. My brother has started drinking a lot and has also told me that he's transgender, just as I am (we're both trans women btw). I need to talk to him about these things, but I'm scared.

As far as his transition is concerned, I want to help him open up and actually let the woman out. I've been dealing with it since my 13th birthday and have a lot of advice I want to share. And, of course, I want him to take control of his drinking habits for a lot of reasons.

The thing is, he doesn't listen. He always has to be right and finds a way to correct nearly anything I say. I feel like he believes I'm not capable of saying anything worthwhile based solely on our age difference. He's also got quite a temper. He doesn't ever get physical, so don't worry there, but he yells quite loudly and it's easy to set him off. It seems like anytime I contradict him he blows his stack and starts screaming.

I love my brother and I know he loves me. He knows I have zero confidence in myself and he also knows that I shut down when people are angry. Even if they aren't mad at me. I want to help, but I'm too afraid to say anything.

So, how am I supposed to handle this? I know I need to do something, not just for him, but for myself as well; for my own growth and piece of mind.