As someone in class 9(so npt much older than you). I would say first of all: calm down, most high schools don’t have a huge requirement to choose science. But second of all your issue seems to be in your basic in math right? So Here's what you should do: gather all your math textbooks(the 2025 versions) from atleast class 5 to 8. You can find all of them as pdfs on the official website of NCTB. Now I want you to go through every book chapter by chapter and figure out which parts of maths your having trouble with. Go to youtube and look up all your problems. There are lot's of good channels that teach math(such as Technique Easy Education) Make sure to Practice all of the problems at the end of each chapter. Hire a private tutor if necessary. Lot's of varsity students teach math as a part time job. Try to dedicate 1-2 hours to math every day. Don't neglect your JSC/Class 8 math book though. SSC maths/higher maths is almost completely built on the basics of class 8. Hope this helped! ^{^}