In fact, I sympathize with you, because I am good at math, so please believe me. Mathematics is definitely not a rote learning subject. You should learn and use flexibly on the basis of understanding the knowledge points. Thinking more and doing problems properly, especially some representative problems, can help you have better solid knowledge. But not too much, it will waste time and make you feel tired of learning.

In view of your carelessness, I suggest that when you do the problem at ordinary times, you should first examine the problem slowly, then answer it quickly, and understand the meaning of the problem before answering it, which will be helpful to you.

As for your slow answer, I suggest you do more questions. Practice makes perfect, so it will be quick. In addition, don't look at your watch during the exam, which will only make you more and more anxious. If you don't finish, you won't finish, and you don't care about these points. In fact, the degree of miscalculation when you answer questions in anxiety is far greater than that when you type a few questions carefully. In addition, I suggest that you don't study Olympic Mathematics, which will delay your time and not help math. Olympiad pays attention to abstract thinking, but mathematics does not. Those with poor foundation can also learn.

Sleeping affects learning. I suggest you go to bed 10, not too late.