Hello and welcome. Sounds like your are desparate to reclaim your home and your families life. I always felt that difficult child sucked so much energy out of the room, that there was nothing left for the rest of the family. Hang in there. You aren't alone.
As we tell every new member, we need some background info to understand what's going on. 11yr olds are on the cusp of puberty and not very pretty to deal with. I wish there was some place 11 to 15 yr olds could go to be miserable all by themselves but it ends up they are ours to deal with.
Below is the link to the forum help page. It will give you some info on what the abbreviations mean and how to do a profile signature. It's difficult for us old timers to keep all the stories straight. It's a good resource too.
http://www.conductdisorders.com/forum/f7/
Can you tell us a bit more about your child?
What sort of behaviors you are dealing with?
How does she do in school?
Does she have friends?
How does she spend her free time?
How are her grades?
Who lives in her home with her?
How long have you noticed difficult and challenging behavior?
How does she get along with siblings?
Just a few questions to get you started. Obviously, we would never diagnose anything. All we can do is share our experiences and what we did and what didn't work. Of course, we are here to offer you any support and suggestions we can give.