I am going to condense this as much as possible.
I am 16 years old, older brother to an 11 year old name Nicholas. During his infancy/toddler stage of life, he was attached to his mother (also mine). When my brother was about 4 she passed away from a sever asthma attack right in front of him. We then moved to my fathers mothers house who around the same time had a stroke and a heart attack. She was pronounced completely disabled and unable to walk. She lost control of her whole lower body. My father was taking care of me, my younger brother and my grandma. He couldn't take the stress in his life so he resorted his stress towards drugs (heroin to be exact). He was a constant user and got up to the point where he was spending around 60-100 dollars a day just on heroin. After my grandmother passed away from natural causes, he cracked and couldn't take it anymore. He used more and more, and stopped being the dedicated and hard working father he was. When I was 13 and Nicholas was 7, we got taken away from our homes and a good friend took us in temporarily untill my dad went through rehab. My dad could't go to rehab willingly, as he was too far into his addiction. Long story short, my dads sister (my aunt) screwed my dad over with my grandmas house money and he was broke, literally nothing. He passed away from an overdose shortly after that.
Now, me and my brother are living with my 22 year old sister, who has severe mental problems due to a traumatic childhood, similar to ours. Now, to the real problem. Several psychiatrists diagnosed him with severe ADHD and oppositional defiance. He simply cannot function with other children and has a lot of emotions going through him constantly, causing him to break at any moment. His attacks include biting, scratching, screaming, cursing, etc... Just recently, the good friend of the family that took us in a while back gave up on him and refuses to speak with him anymore, due to his behavior. She has a son with cerebal pausy and Nicholas has had several aggressive situations with him regarding his life. He also showed signs of sexual activity towards her younger daughter and showed aggression towards their pet dog. He is now more alone then ever.
We have him in a special behavioral school with about 13 kids in his class and after school there is a program we get for free due to our financial situation that keeps him untill for a few more hours.
Today, he was unlike any other nicholas. He started cursing telling us to go "you know what" ourselves. He started banging and we asked him to stop and he refused. He started screaming and we tried to reason with him but he just kept saying "cool" after every word we said. He would randomly start bursting out into crying episodes, as well as severe laughing episodes. As we left the room he said "If I were you guys, I would stay awake tonight."
I just dont know what to do anymore. As a brother, I cannot do anything for him anymore and I just want this to go away and for us to be happy. I cannot deal with this any longer, it is physically and mentally wearing me apart and my sister is on the brink of suicide. The only thing keeping her from not committing suicide is the idea of us losing another loved one.
Please, send this to someone who may help us, or help us any way you can, please, I cannot live like this. I need to get help for my brother, even if I have to die trying.