I don't think it is difficult to change this state. You can try:

(1). As far as you are concerned, you usually have ideas when doing problems. Then try to find some relatively simple topics every day, relax, and write down the disintegration process step by step while ensuring the correct thinking. Don't pursue speed, but make sure you can calculate correctly and write completely at once. Don't need a lot, 2-3 questions a day is enough; Keep the change. You can practice at ordinary times, and you can choose multiple-choice questions, fill-in-the-blank questions and short-answer questions in your homework.

(2) After completing the first step, I began to try to complete some relatively complicated topics in the same way. Relatively complex means relatively comprehensive, or it needs to be discussed in categories, or it is more troublesome to calculate. Similarly, don't pursue speed, try to get it done at once. Of course, you can simply check it when calculating.

(3). The third step is to focus on those difficult questions, that is, the last 1 and 2 questions in the test paper.

Slowly, you will find that your calculation accuracy is actually very high, so that you won't feel insecure during the exam. If you are in doubt about some calculation results during the exam, put them on hold first, don't panic, finish the rest of the questions first, and then check the questions you are not sure about when you have finished them. Besides, sometimes other topics will inspire you.