You can try to read some math textbooks (for example, taking mathematical analysis instead of high numbers, focusing on strengthening analytical ability rather than formula setting ability), and match them with some other foreign math books (for example, Calculus Slaughter the Dragon, Sword of Eternal Love, comic series of Om Society, etc.). ) to adjust their interests and review some math skills. ...
In addition to attending classes and reading books, the cultivation of mathematical ability is absolutely inseparable from a lot of practice (to put it bluntly, it is a tactic to deal with college entrance examination questions) ... It is an eternal truth that practice makes perfect. This process may be long and boring, but it will definitely benefit you a lot. I think we should pay more attention to the problem of proof than the problem of formula calculation.
In daily life, we can also link problems with mathematics to think about problems and cultivate mathematical thinking. Don't think it's BT
After you feel that you have mastered it a little better, you can find some books such as mathematical models to read, which will definitely help the theoretical research at the graduate level.
You still have two years, it's not too late. Just take some classes that are useless for your future development. Spend more time on math, and you will never regret it.