It's simple, as long as you take the time. Read the textbook first, understand the theorem, do the exercises after class immediately after reading the examples, and then check the answers. Can it be done in half a day? No, you just spent the whole day and rested at night. Can you do the examples in the textbook without looking at the answers? Then you can do exercises on extracurricular materials. Mathematics is to understand and keep doing problems. Efficiency is up to you. You have to make a daily plan for yourself. For example, how many pages to read and how many questions to do every day. Actually, there is no need to find a teacher. You can teach yourself by reading textbooks. I was sick and asked for leave in the second grade. Reading by yourself in the hospital bed, I found that I can understand everything. I didn't listen to the teacher, but read a chapter quickly. Active learning is faster than passive learning. When you really don't want to learn, find a teacher to study with you.