Beyong Frustrated

I am mother first and for most. I have four beautiful brilliant children. I have been married for almost 5 years and been with him for eight years all together. I have a beautiful 11 year daughter that has been dealing with some issues of her own since she was about I want to say truely around 4 years old. She is beyond defiant she is disrespectful, she always has something to say back, she is mulniplitive with everything, she lies to your face and will believe it to the fullest. The list can go on and on but she is a beautiful, creative, bright, funny, caring girl. My problem is this, my family is falling apart due to all the issues we all have to face on a day to day basis. I am tired and so stressed out my husband is tired and stressed out my other three children are not wanting to be bothered with her. I as a mother hate the fact that she has dug her self this deep and has created this whole for her self and every time we throw her a hand she bites it and then spits it out. We have done everything for her therapy, family therapy, a fourty-five day stay, doctors, medications, and nothing. She will tell you I dont know why I do it. I am at such at a loss as to what to do with her. I do not want to give up on her at all but I have three other children to take are of as well as my house hold and I can not do it anymore. My mental health is affected as well as my husbands and my other children as well with all the fighting everyday. Depression has hit my husband he wants to leave and on the other hand he wants to stay because he loves us. Depression has hit me because I love my daughter but can not deal with anymore. It is like a cloud of doom everyday when I come home from work and I am tired of it. I am beyond frustrated.......