>>10125033I used to be garbage at math (talking about consistently getting less than 30% on high school tests) due to a perceived lack of interest + lack of work ethic + immaturity. Now I'm a math major and I'm doing quite well.
Depending on what you're struggling with, and the amount of work you put in, the answer will be different, but if you failed calculus thrice it obviously means you don't understand the fundamental principles on which it relies.
I used to have a mediocre understanding of calc and I found that doing some newtonian mechanics helped me understand what exactly it represented.
What's a derivative, how do you express it with a limit, what's a limit in the first place, why can you derive a function to study its behavior, etc. Make sure you completely, fully understand those things. Don't learn them buy heart, just take the time to picture what those concepts represent and how they interact with each other.
The next step is doing a lot of exercises to apply your theoretical understanding of the subject.
But really, what fucked me over so many times in math was that I thought I understood a subject, when in fact, my understanding was vague at best. You might be in the same situation.