My mum has said hurtful things too.
I had to cut myself off from my family completely before I eventually mended the ties. You may not have to resort to that. I know it is not as easy. "Caustic are the ties that bind" (Trivium)

My mum would say "what's good enough for me is more than good enough for you" "beggars cant be choosers" "you are bone idle" "your not confident enough to be anything" "one day you will thank us for putting a roof over your head"
My step-dad when I was 18 was mad he could no longer "control" me as I rebelled big style. He punched through the glass in the door. Dug his fingers into my head "and said you will listen to me LITTLE GIRL, your a LITTLE GIRL" Other times "you don't have a mind of your own" "your fathers brainwashed you"

When I was ill they would phone my boyf to see if I was behaving. My boyf knew more about what the doctors told my parents than me! When I found out I was incandescent with anger. They spoke of someone on my mums side. I was a "genuine" case but they told them they didn't find anything "wrong" with me.
My parent were like- any other guy would have run a mile and we don't blame them (cause I had a psychotic breakdown)

So my boyf would always say "I am not your step dad" when I was mad at him (my mothers fiery temper didn't skip a generation) But that was three years down the line and through reading and thinking I had actually, looked past his faults - my step dad. It was my mum and me who were at logger heads. And the boyf in question managed to make an even bigger rift between me and family. My mum said my boyf would "fight with his own shadow" and it was accurate. I said this and he exploded. It was like we used to try and see who had had a worse childhood as he felt he was so hard done by coming from a big family.
I started to even use his jokes.
He made me even more messed up. Saying I needed help, when what I needed was a life of my own.
So I had become trapped in that cycle of helplessness and landed from the frying pan into the fire.
I too just wanted to be free/independent
When it all hit the fan and I landed in the hospital, I luckily had a relative who was there for me. Her and my mum never seen eye to eye. She helped me a lot. I had felt unbelievably alone "have I run too far to come home"

What I am saying is, you know you need to escape this awful predicament you are in, you have to completely detach yourself from it. I know. Because I had to do the same with my ill grandmother.
Put your health above all else . And for the sake of your health you need to cut loose on your own.
Get in touch with local services to see to your mum, and get yourself help- go to the GP and tell them, and you can be referred to psychiatry. Tell them you are suicidal. Tell A and E you are suicidal and they will not turn you away. If anything at least you can get something to alleviate the way you are feeling. be safe