Hi there, I agree with what the others have said so I am going to focus more on another issue, it may not apply to you but I'll share my experience. I too have a child who can be very aggressive and say things that are obviously egocentric and mine too is on the spectrum. My son does not steal and he sounds lower functioning cognitively than yours, but he also has attachment challenges and it was thought when he was young, ptsd.
Have you ever read the books by Ross Greene? He wrote The Explosive Child and it might be a help to you. Also many like What Your Explosive Child is Trying to Tell You by Doug Riley.
We all naturally try consequences, taking away things, restricting privileges and/or earning things with appropriate behaviors. For my son if a consequence or reward is very powerful (such as his high interest or obsessive subjects...for him missing a NASCAR race on TV or swimming in our pool or use of his samsung galaxy player) they can't be used as rewards or punishments. Kids with autism and other conditions obsess and focus on these things and they can't make a brain shift to saying...oh if I'd just act better I could earn it back. They are overwhelmed with focus on getting it back, life is ruined and over without the item. It is fight of flight for them over things that for us are more minor. They do not have the underlying skills to work it through and make a better decision.
Last night my son started focusing on the pool, I negotiated that if he could show me he was in control of his blurting (saying in appropriate things) we could go, so first we were going to two places and he needed to show me. It would have taken no more than twenty minutes. We didn't get two blocks away when he was swearing at me because he was so worried about the pool. You will never let me go, you should never have adopted me, you are the problem! he was banging on the back of the car seats and kicking the floor of the car. Then woudl scream at the top of his lungs YOU SHUT UP and then just a piercing scream. OK, clearly not in a place where we can go to the pool, have to allow his brain to calm (when I talk or try to calm him in those moments he starts all over...it is like a storm that needs to pass, anger makes it much worse, and it is HARD not to be angry when they are saying and doing things that are so mean sounding). I kept driving went to a parking lot of a thrift store. He needed some new shorts (not a reward he NEEDED them ...growth spurt! and school starts MON, but it happens he loves to get new clothes) so I was working to shift his thinking. He refused to go in and blocked me but I just waited him out. I finally saw he was calmer, i told him he could come in if he wanted but I was going in. He joined me minutes later and asked where the mens section was (heck he is only 140 and at age 15 I have a hard time, can't imagine your son!). ..... and it was like nothing happened. That makes me crazy but I am grateful for it. He really needed to focus on something else. We found two pair of shorts thank heaven or he would be wearing the same one pair he has every day, lol...I will get more next week but cut things off on a good note. No way we could do the pool but not as a consequence, he clearly was not in control of his impulses/tics/whatever he goes through and safety issues are not negotiable. He had a race starting on TV and I said if he could show me for ten minutes he had continued to turn it around we could get dinner and have a "race party" at our house. (a party to him is just calling it a party, not what we call a party). He was thrilled. He has a great night after that. I was spent of course, it ended up to be two hours of intense behavior management (and we have had whole days)...but no aggression. I have learned I can't say, well if you do that then we wont go to the pool for a week! He woudl have ended up with a 911 call. It just doesn't work for him. I have had to say we can't do X until I can see your medications are working etc. if it is a safety issue, and I know it will cause him stress and probably more behaviors but again, if it is a safety thing, it is not a choice so those are the only times.
Others would disagree probably, and I know for sure traditional behavior people would disagree. But taking the neurobehavioral approach of teaching skills, responding to how their brains function, helping with sensory issues, working to distract them, etc...really does make a huge difference. It takes consistency and NOT losing your cool which if your boyfriend can't get on board with may mean you need to see him when your son is not around if at all. I have no dating life right now, it is too complex to try to get someone to understand this kind of condition. I only have ONE chance to do the mommy thing right. I am not saying I dont count or that I dont deserve it, if you can work it out to keep it separate that might work!
I also have in home (well they take him out a lot because that is his goal) Integrated Listening Systems (ILS) workers three times weekly which could be increased if needed. Do you have any support still from the county? Can you go through the disability people or mental health people instead of the courts for support? That is what we do but I know every community is a little different.
Anyway, those books can help you think of different ways to work on this stuff, and it is a big relief when it works I can't do it exactly as the books say, with all the cognitive issues and we have seizures that change his mood suddenly too. BUT it made the difference in my coping and our being able to live in a home.
I wish you well, not sure I made sense here, but feel free to ask questions....HUGS, you are not alone by any means! This is a hard road.