I am so sorry you haven't received any reply's to your very important and hard to sort out problem with your kitty. weekends are slow on the forum to start with and being that its a long weekend..Thanksgiving here in Canada I myself have been away.
I'm not sure I can be of much help. aggression towards another cat can have many reasons. I will send you a site that perhaps can give you some insight.
best of luck and no don't give up.....
http://www.sniksnak.com/cathealth/aggression.html