i hate myself and my life

My life has always been messed up. The earliest memory I can remember was of my mum holding one of my arms and dragging my out the front door of my first home and my other hand reaching out for my dad who stood and watched. I was screaming and crying. I didn’t want to go.
I’ve lived in many homes since my mum and dad got divorced. And mum has had many boyfriends. One was Gavin who had a son. They were really nice at first but I got scared of Gavin. One day during one of Their arguments I was hungry so I went into the room they were in a whispered to mum “can I have a treat”. Mum stood up and said to Gavin, “look! Even ******’s scared of you!”
Before my mum married my dad she married someone else and had my older sister *****. MY dad had also married once before and had a daughter called ****.
But the worst boyfriend was Stephen. I was never a big eater and 1 slice of toast was sufficient for me in the morning but of course, Stephen wanted me to eat 2 and always put me down, every morning. He already had 2 girls, one older then me called ***** and one younger one called ****. I liked them at first but later found out they had been telling Stephen that I did things that I never did, getting me into trouble. I was mentally abused to the point I was diagnosed with severe depression and my psychologist canceled appointments to get me in. Mum and Stephen had twin girls, **** and ***** but they alter divorced. It wasn’t until they divorced that I realized, 1. Stephen was only being rude to me to get back at mum and 2. Mum had caused the depression, not Stephen.
Now, my dad has re-married and I have a step sister and a step brother. My dad reduced the time he saw me to every 2 weeks instead of every week.
I have felt a knife pressed against my chest before but I didn’t push because I thought of my friends. I was 10 at the time. I am now 13, I cut, I have a lot of suicidal thought and I have ultimate lows in my mood. My grandma no-longer likes me, claiming I have anger issues. I am left alone with my mum and the twins, who drive me absolutely insane. My mum has called me horrific names, and told me she wishes I was never born (of course she denies it now) and said quite often “kids, why have them?”
She hates me and puts on a sweet fake act whenever I have friends around.
I honestly don’t know if life I worth living anymore…