Oh my, I'm so sorry you are going through this very difficult situation.
Here's the but....I believe this dog is extremely tramatized at this point. If it is acting out, attacking your other dogs, you etc, it is obvious this dog is not in a good situation, the stress level has to be unreal for this animal. All the things this dog has went through day in and day out is truly inconceivable to me. The only thing the dog is relating to is that it is being tortured every single day.
I too believe it needs in a home with no other pets and one ower, to start from the beginning......building trust with this dog, at this point is going to take some time and work up patiently from there. It will take some work, but I do not believe this dog is not a lost cause.
I am in no way putting you down. You have reacted to not having the love and companionship that comes from a pet and you have responded irrationally because of the difficult dog, which has only intensified the whole situtation. Please step back, take a deep breath and truly assess what needs to be done to give this dog some quality of life. Once you face that fact and move forward you will all benefit in the long run.
Think how miserable this is making you, it's not fair to your other dogs, they too have to be stressed everyday. Most of all this dog should not have to live this way. It's not a failure on your part, it simply is the entire home needs to change to help this dog. I give the utmost respect and admire a person that does what is necessary to provide and make the best life for a pet and sometimes that means letting them go to a better life that fits them....not you.
I beg you, please rehome this dog and give it a good life, along with yourself and your other dogs.
__________________ Tena & Zhoie  Sweet Little Miracle |