Desperate mum

Im a single mum to a 13 year old boy with ASD. He is everything to me and I fought many battles to get him diagnosed, to learn about the condition, the support at school and to have the independence he strives for. Sadly now I am failing to cope. Most recently, he got very angry about me mentioning to my step father how the dog had slipped his collar on a walk but i caught him and is OK. He screamed that I was telling everyone (I hadn't). I said if he told me something upset him I wouldn't say about it. I go to another room to see my mum creating a bit of space and he follows screaming I was talking about it again. Both me and my mum explained I wasn't to which he screams I'm a whore and he hopes I die of cancer, which my aunt has, just a couple of days ago. My mum spent a long time trying to talk to my son, explaining I had no idea and that I'm sorry it upset him so much but his having none of it and completely ignoring me. I'm seriously struggling. I feel I'm a verbal punchbag. He says things to embarrass me like telling my dad I said my dad should give me £5000. Will argue with everything I say. Never wants to do anything other than play his games. Fine with everybody else! I believe he hates me. It's been a long long journey and I'm struggling to keep myself together. Maybe I'm selfish thinking about how I feel or depressed, I'm aware I'm sensitive but those sort of words every so often hurt so much. Sorry for the ramble, I'm praying for some constructive thoughts please x