Your brother cannot get unbanned while you are banned. That is simply the way it is, I'm sorry.
From what I heard you raged on these forums and that's just not cool. I don't really know how bad your actions were, but if I were admin I would require proof of you and your bro on at the same time in Gmod and reduce your ban to less than a perma for your bros sake.
Disrespect is not lightly tolerated however, and you would have to talk to those you have offended.