How do i get help for this problem?

I've been in mental health treatment for a while. They aren't really helping me and I cannot be open with them about my thoughts because they threaten to lock me up.

I am starting to realize the cause of many of my problems.

I was born with autism. Had an alright childhood. Didn't have many friends though. Was bullied most my life but my parents were good to me. Was held back several times throughout school. I was always the weird kid other students didn't want to associate with.

When I was 18 I met someone who befriended me and invited me to move out of my parents to live with. Looking back I think he saw I was weird and wanted to use me as a guinea pig. I lived with him for 4 years and have since noticed he was trying to train me to become a serial killer. He often compared himself to Charles Manson and the antichrist and encouraged psychopathic behaviors and beliefs.

Much time has passed since then. I am unable to have healthy relationships with others. I have almost constant homicidal thoughts I cannot tell anyone about. I live in constant paranoia and trust nobody. I see good in nobody and honestly feel going on a killing spree might be the morally right thing to do as humans should be exterminated for their own good.

I've held back out of not wanting to become that. I desire a better life but don't know how. I no longer have much emotions other than anger and humor. Most the time I cannot feel anything at all. It's to the point where I've witnessed murders and felt nothing. Crying or complaining about anything is a sign that you should kill yourself. When I read about mass shooters I understand exactly how they felt. I have little desire to do much else.

I want to be a better person and have a successful life though. I do not know how to ask for help. My autism further complicates my ability to talk to psychiatrists who dismiss me as crazy and push pills and threaten to put me in a psych ward when I mention my thoughts.

How do I improve my life.