I think since you have a good personal condition, you might as well buy a junior high school math course. The questions in it are not easy to do, and some of them are biased, but you don't have to do them. You just need to think about it and read the analysis in the book. I took such a book when I was in junior high school, and other teaching AIDS have never used it. It's really good to exercise your thinking with math problems. You can try.

And many of its topics are very interesting, which is very suitable for middle school students to explore.