(England) can my mother make decisions for me because I have an autism diagnosis?

I feel paranoid even writing this but I’m 19 and I’m scared I’m going to be forced to leave uni and be stripped of my legal autonomy.

My mum has threatened for a while now that if I don’t listen to her she’ll get me pulled out of uni using my autism diagnosis. She’s now fully said she’ll claim I’m not competent enough to live alone and will force me to live with her my whole life, take me out uni, make medical decisions for me.

I got diagnosed with autism at 17, just before i turned 18. I’ve gotten through my first year of uni living not only way from home but on another continent entirely (I live in England, my family is in Africa) and I feel like she shouldn’t be able to do what she’s threatening but I’m worried she can.

So can she? Is there even any legal loopholes she can try to exploit? What can I do to protect myself against this?