How can I refute and even stop it

I would rather have no long vacations at all and take lessons at school every week than spend this winter vacation at home. When I am staying at home, for the majority of every day, my phone is kept by my mother. Although I am not way too dependent on my phone, this does lead to some problems.

We students in our university usually contact each other through WeChat on both smartphones and computers. I knew what my mother would do to WeChat on my phone so I deleted all the chat history mentioning her. However, it has only helped me get rid of a part of problems. My mother sometimes judges what I talk to my schoolmates.

Our school has a Schoolmate Circle for people who currently belong to our university or graduated from it. We share our posts and leave our comments on the posts there. The platform is a mini program of WeChat. The users can see their own posts on their personal homepage, and by clicking on the button, "comments", on that page they can see the history of their own comments, and by clicking on each history item they can go to the corresponding post where they left that comment. I had never thought that my mother would get on that platform until she started to speak ill of what I posted and commented. For example, today, she told me that my comments were so stupid and low-end that I shouldn't leave any comments any more. I left several posts complaining about her and I wish I had deleted them before she could see them, for not until I found she began to use the mini program on my phone did I came to realize the necessity to delete the "inappropriate" posts. I am still extremely grateful to myself for clearing all the private messages there in time without their being read by my mother.