Hi and thanks for your letter.
Sounds as though you are having a hard time at home. Having a mum for a teacher can be a good or not so good experience. Mum should understand that it's not easy keeping up with homework not give you more.
You seem to know that you are good in school so maybe you can have a word with your teacher, they might understand. Some parents do put pressure on their children to be very high achievers and nothing is ever good enough. This can feel very difficult and exhausting.
I am wondering whether mum has actually called you stupid or is this how she makes you feel? Have a think about telling her how she is making you feel right now. Or even write something down for her. Maybe you could talk to one of your teachers about all the extra pressure from home.
You have made a start at trying to make changes by writing to me. I wonder how you would feel about talking to a ChildLine counsellor as well? If you call 0800 1111 you can speak to a counsellor or login to the website and come and have an online 1-2-1 chat.
Take care
Sam