Is it normal that my mother is making me self-destruct

I'm 21 years old and its taken me almost that long to realise my mother is ruining my life.

My parents divorced when I was 10, my mother ended up getting full custody. As soon as everything was finalised we moved house, went to different schools, everything changed. My father was an alcoholic, had manic depression and was incredibly bitter that he was the one being divorced. I think this, alongside general low self-esteem made my mother obsessive? She became incredibly controlling. She started putting a huge amount of pressure on us both to do well at school, telling us she got divorced, moved house, took a stressful higher paying job, put us both in private schools so we'd become successful, get A* grades in everything and get good jobs etc. She stopped letting me go out so much in the evenings and on weekends, because she 'didn't go through the divorce and pay for private schools for us to socialise and become failures.' Consequently, I didn't have much of a social life around this time. I used to get really good grades however, which I think reinforced my mother's behaviour, but really it's just because I loved school because I could see my friends and get away from home, so I'd work hard at it. Everything got too much during my GCSEs (grade 10/11), I became depressed and started self-harming and when my mother found out she took me to counselling. Everyone thought it was because of the divorce and the lack of a father figure, but really it was because of her. I didn't say anything however, because I was afraid I'd upset her. The depression made my grades plummet and she went ballistic as a result following one parents evening. I was still predicted B and C grades, but when we got home she threw out a tonne of my favourite things and locked some of my more important possessions in the boot of her car, saying I wouldn't get them back until my grades improved, that I was an embarrassment to her, selfish and a failure. When I finally did get my things back two or three months later (CDs, records, a huge shell I found in Dorset and liked) a lot of the CDs and records were damaged and the shell had most of the tips of the spikes broken off :( I also stopped going to counselling around this time, partly because I felt selfish for making her drive me there and partly because I didn't feel like it was working. My grades continued to be good, but I started self-harming more, becoming more antisocial and feeling irrational all the time. This continued and got worse throughout college.

I couldn't wait to go to university and escape her. Things progressively started to get better at university. I became more confident, I stopped self-harming so much. I even got a girlfriend. Every time I have to come home or be around her however, I start thinking irrationally. I get annoyed, angry or upset really quickly. I don't feel like I can cope or think normally if I don't have a razor with me. We argue all the time. I feel suffocated by her, her expectations of me, her desire to control everything, her anxieties that I don't eat enough or take care of myself or that something will happen to me and then she'll be perceived as a failure of a parent by everyone. Every time I spend time with her I hate her more and more. I hate how she makes me feel. I feel like she's ruining my life. I hate her so much.