Dude, you're not the only one who can't count high. Do you dare to say that you finished your advanced math in just a few days after you went to college? Learning to learn is the patent of a few people. Most people are not easy, but they may get better grades than you. A month means nothing. Since you are willing to work hard, passing the exam is not a problem at all. College exams are all basic, very basic. It's just that the course is really harder than before.
Don't think about anything, just work hard as always, the foundation doesn't mean anything. You will gradually find that the foundation of high school has little effect on college study, but it will really affect you a lot psychologically.