I wish I knew the answer, @Susan7654
it's breaking my heart at the moment. Older son (autistic at the level that he 'needs substantial support') has acted like he hates me for some years now. Endless deceit over screens, endless lies and trickery, endless explosions when it's time to go to bed. Won't go to school.
It's all very well people saying 'you have to impose boundaries and stick to them'. I agree, 100%. But doing it when faced with an explosive and resistant 16yo is beyond me.
My health is unfortunately really not good and in the end I sent him to his father's. Fortunately that was actually an option. We've had one meeting since with his support worker there and it was very tense. No shouting, but a horrible distance between us and I'm afraid that for the first time the distance was on my side as well as his. It's breaking my heart, but I can't handle the lies and fighting. Everything is my fault, nothing is his.
So I'm sorry but no advice. There's all the standard stuff like 'try to do things together to build a bond', 'keep the boundaries intact' etc, but honestly, nothing has worked for me. I am not sure we will ever get over this.