>>16699578 (OP)Do it in a problem-centric way. Attempt problems instead of passively reading the text or watching lectures. Passive approach feels great because it hardly uses your brain. Focus on HW, Quizzes, old exams problems. Textbook problems and problem books come later.
Check problem 1, try it with what you know, refer back to text, try again, check older similar problems from HW and whatnot, try again, ask classmates, try again, ask TA, try again, ask online, try again. Rinse and repeat. Check the solution after you've made a decent attempt like the next day or next week. Compare it. Identify the wrong step caused by your misunderstanding, mistake, lack of knowledge. Take a note of this. Regularly review this collection of mistakes. If you really have brain issues that make it difficult to remember things despite doing a fuck ton of problems, try Anki. You only need to learn 2 features of Anki. Reverse cards and cloze.
A good mindset to have: https://math.stackexchange.com/questions/33656/whats-better-strategy-to-handle-tons-of-formulas-definitions/33987#33987
If you have great difficulties solving the problems in a calculus course, you most likely lack:
1. Algebra skills. Don't look down on it. AOPS Prealgbra and Intro to Algebra are enough.
2. Problem solving skills. At least expose yourself to some of the mindset and techniques from Paul Zeitz's The Art and Craft of Problem Solving.
3. Proof writing skills. Just use Hammack's Book of Proof.