Hi all

I'm new here, and I have a question.
I'm 19 years old and my brother is 17.
We lost our mother when I was 15 and he was 13.
My father is not the affectionate type and disagrees with counseling and such.
He was also a wreck when my mother past away, and I had to take on the role of caregiver.
My brother and dad have never been to grief counseling of any kind, but as soon as I got into college, I enrolled in counseling programs there for grief and for DBT.
My brother is very isolated and he never goes outside. He dropped out of school, but he is now enrolled in an online school (American School). He hardly goes outside and is on the computer at all times. My brother is also very aggressive and violent. If he does not get what he wants, he reacts in an abusive way.
For example, I was doing Insanity, an exercise program, in the basement, where my brother's second room is. He was angry because he could not sleep. And my brother has his actual room on the second floor, so I told him to sleep there. My brother was not comprising to this and as soon as my dad left to get groceries, my brother charged out of his room and hit me continuously and strangled me.
I am still shaken and very angry about this event as is my dad.
We both do not know what to do. My dad is also afraid of him and believes that if he won't go to school, he won't go anywhere.
I feel like my brother needs an eye opener or some outside force to literally grab him out of the house so that he can get help.
I have tried for about 2 years contacting various family members to see what I can do, but I'm truly lost right now.
If there is any advice that you all can give, I will more than gladly take it
Thank you