How do I deal with my mum?

I love her but I really don’t like her sometimes! She makes it really difficult to live in the same house as her. Ill do a list iutll be easier :) I know im going to sound really really selfish but it really is starting to get me down

1. she calls me fat all the time and digs me about my belly in sly little nasty ways, when she’s obese, so I don’t understand that
2. she makes it obvious that I was never meant to be born, that I was a mistake. That really upsets me because other people who were using a condom and on the pill might say that I was a miracle but no, I was a mistake
3. she turns everything into a competition. For example, if I have a sore foot and I try to tell her about it because im in pain or im worrying or something, she doesnt offer advice, she just starts on about how she broke her ankle and it really hurt and its playing up again and goes on and on about it when I really want some advice
4. she has no sense of humour, I have quite a sarcastic, sadistic, dry sense of humour and she never gets any of my jokes, and I understand that she might not get them but she always takes offence at them and I dont understand how she cant hear the tone of my voice
5. she fights with my brother and my dad quite a lot
6. she blamed me when the shower got blocked up because I have long hair, but she does too, and so does my brother. So it cant have only been me.
7. she belittles my efforts at everything, we recently bought a load of furniture for me from ikea, when it arrived she had a go at me for not washing up, and then the next day I tried really hard to not piss her off, I washed four lots of clothes and put the largest piece of furniture together by myself because my dad wouldnt help me. Then she came home and tbh, she did try to be nice, but then when I asked her for a bit of help putting these funny things on my desk (she called them runners) she had a go at me for expecting her to do everyhting for me.
8. she tells me its a waste of my time writing stories and books when she knows very well, that I would really like to be an author, I know that its not going to happen but its a hobby for now, I like it, I dont see why im not allowed to do something I like without it being called a waste of time because she thinks im sh*t! Oo, I got a bit anoyed at that last one, well anyway, it wouls be great if anyone could tell what to do Be brutal if you think im a self-absorbed cow then tell me (im gonna regret saying that right?!) And if any other 15 year olds feel this way please tell me because I kinda need to know whether im a retard or whether it happens a lot. Thanks

(btw, she does a lot more than just those few things but those are the worst things :) )