I have a brother that is 3 years younger than me and boy am I glad he doesn't act like your brother! If I were you I'd hit him. I'm not even kidding. A good fist fight between me and my brother brought us much closer together. Then again, it's been at least 10 years since our last fist fight. Now we just argue and call each other names, don't speak to each other for a week and then forget about it and life is back to normal.
I'd tell him to grow up and start acting mature because you're each other's only sibling and you want to have a good relationship together. Or, he can stop all contact with you and ask for him not to post your PRIVATE life together on a PUBLIC site such as LJ. He's 22 and you're 25 - there's no reason why he should be acting like a child. If he has a problem with you or something you say then tell him to tell you and not the entire world through LJ. Ask him what his problem is, what is it that you did or what happened to cause him to have so much hate towards you. Sit down with your entire family - mom and dad - and have this talk. Let your parents know what's going on. What's he's doing is out right immature and needs to stop.
Whatever you do, good luck. I have 4 brothers and am really thanking god none are like yours. We may not all get along but we tolerate each other and act matrue. My 18 year old step brother doesn't really care for me but we get along. He's still family.