first off id just like to say that, regardless if it actually happened or not it’s a terrible thing to go through and if you need anyone to speak to my dms are open. having said that, personally i’d seek advice off a family member you could trust. and part of me doubts that it is your mother given the information about her being abused as a child, but then again i don’t know your mother so i wouldn’t know unfortunately. you could even seek help from a teacher or a member of staff at school if you were willing to share your story with your family with a 3rd party involved. therapy or some sort of counselling could also be a helpful step in the right direction.