Trying to maintain a balance....

I've been out of work for almost 5 years now. My anxiety/depression has been so severe that I cannot concentrate or focus and I've been having alot of panic attacks. I'm fairly certain that I am bi-polar (or manic/depressive, as they used to call it) and am waiting to get scheduled for an evaluation so that I can have a proper diagnosis and proper medication because I'm tired of living like this.
I'm also living with a 12 year old (almost 12) who exhibits signs that she, also, may be bi-polar, and a brother who is probably the most irritating man I've ever known.
He's been living with me since January 2006, and since that time he has not even covered his own personal expenses. He sells books on the internet and has cost us (me) countless thousands of dollars heating uninsulated spaces to store his books (and complaining that they are not warm enough), and cluttered my house with thousands of books, most of which are only worth about $1.
He doesn't clean up after himself, and his rooms (on the second floor) have such a layer of dust-bunnies (with a path through them where he moves around) that they keep creeping down the stairs. These dust-bunnies are such that i'm afraid that they are going to rise up and attack.
Every time that I try to talk to him about any issue he bites my head off. He has little or no respect for me or my opinion. He spends money as if he has some.
For the (at least) third time he spent some of the mortgage money and I cannot pay the mortgage on time. He spent it going out to eat and purchasing lots of fancy envelopes to mail out his $1 books in when they sell.
I'm so sick of living like this that I cannot breathe! If I thought that he had a chance of taking care of himself I'd throw him out in a heartbeat, but I'm fairly certain that he cannot.
Meanwhile, I have a pre-pubescent girl who takes out every thing on me. Usually she screams, berates, and insults me almost every morning and refuses to do anything I tell her to do. I'm working with her and her counselor to try to improve her behavior, but it is very slow going.
I'd say that I'm having another nervous breakdown, but they don't call it that anymore. I wish that they would stop changing the terms for things and actually give out the information about conditions and treatments so that I could have a chance to help myself without waiting for the doctors to get around to seeing me.