I'm so sorry you're dealing with this.
Does your son take ADHD medication? If not, this may make an enormous difference in his life and yours.
If he already takes it, does it make a difference? If it doesn't please go back to your doctor and investigate something that works better for him.
My son was diagnosed with severe ADHD when he was 5. (his special ed teacher at the age of 9 said he had the most severe hyperactive ADHD she had ever seen in 40 years of teaching...and this was when we felt he was in a much better place after 3 years of support, treatment, medication).
Without medication there was no amount of parenting strategies and love that would help him because we couldn't reach him. Nothing worked and our family was falling apart as this was the exact time my husband had a burnout and depression, family bereavement, another DC who was a baby/toddler, no family support. life was impossible and bleak and I couldn't see it getting any better. My relationship with DH was awful. He was awful to me and the kids, I found myself being awful to the kids. I could not cope with my life.
Only once he was on ADHD medication could we begin to make the changes we needed. Family parenting support based around his needs and ours (he's not the only ND member of the family). Specialist school and out of school care/support. Therapy for everyone at one stage or another.
DC now 13, still on meds, still in special ed but we are at a stage when he can be more independent, cycles to school by himself. He's a lovely, amazing kid.
It sounds like you and the whole family are in a place of overwhelming stress, trauma and a spiral of negative behaviour. Not surprising. You need support and help, and sometimes that means protecting yourself.
Please look for outside support. I don't know who you have in your life but I've been there and it was the absolute worst time of my life - I had never felt so alone because nobody really understood.