I am really sorry to hear that you feel bad after entering the high school.
I am really sorry to hear that you feel bad after entering the high school. I’d like to talk about it with you.
In fact, in your senior high school, your classmates are also new and facing the same problem, so you don’t have to worry too much about it. There is also something that you can do to change this situation. First, try to invite some of your classmates to take part in some activities together after school. This will help you understand each other better than communicating with others. Then, help your classmates when they are in trouble and ask them to help you when you have difficulty.
I believe you will make many new friends and you will have a happy school life there.