I joined this school where it is both a day and boarding school. I was a day student for about 4 years and then now I’ve moved to boarding for the past two semesters. I joined because I hoped it would help my relationship with my parents and my grades. I have important exams in a few months so this is a crucial year for me. I haven’t done very well for the past few exams I’ve had but I think I have a better relationship with my mum. I’m not sure whether I should stay in boarding for the last semester, or go back to being a day student. Any help?
Maybe you should talk to a counselor about your issues with your mum. It is important to do well in school…what is preventing that?
I agree with @bopper, this is an issue that needs to be taken up with a professional and your parents. I am sure it will work out how it should. 
I would suggest going to the place that you can feel at home and able to do your best school work. If it is at school, stay there. If it is at home, be a day student. Sounds simple, but sometimes it is the simple decision of listening to your gut, your inside quiet voice that guides you. If your mom stresses you out, stay in boarding, without guilt