What is the best way to improve my algebraic thinking?

I am ashamed to say I have failed my Calculus class more times than I should have. I have never been good at math but I at least passed.

From studying and practicing, one of the things I have seen that is eating me is that I am too mechanical in my thinking, ie: I need to be told or shown that something can be done so I know I can do it, instead of proactively mixing math knowledge to solve the problem.

I just get extremely stuck in things like that, but I don't know how to improve at it.