As for mathematics, my suggestion is to understand the examples thoroughly. You shouldn't die doing sports. After each problem is finished, even if you can do it, you should sum up the methods and ideas, and then recall whether you have done similar problems recently. Secondly, you must be careful when you do the problem, and you can't make mistakes in every detail. After two years, you will form a good habit of doing problems.
English I think the most important thing is vocabulary. You still have time. You can read more English newspapers and periodicals. Stir up unfamiliar words. Write about 10 every day. Then learn grammar knowledge. You can't lose interest in learning because of the teacher. It is you who suffer.
I think self-study is for students with high learning efficiency and good learning methods.
A summer vacation is not long. As long as you study hard, two months is enough to form a good study habit.
The above is my advice as a person who has experienced the college entrance examination twice ... You can change yourself from now on. I believe you can do it. Come on! ! !