<p>It sounds like you just need to build your confidence up. You wouldn’t have got as far as you have if you weren’t capable–now, you just need to believe that too. </p>
<p>Practice builds confidence. For a lot of practice problems in calc, purchase “3000 Solved Problems in Calculus” (on Amazon)</p>
<p>For help to fill in the areas you’re struggling in or don’t understand, buy “The Calculus Lifesaver” and “How to Ace Calculus: The Streetwise Guide”
also on Amazon. </p>
<p>All three are great books. The last two briefly cover trig and some precalc notes too. </p>
<p>You should do the same for any other subjects you need help with. Find a book that contains a lot of problems and some supplement learning books and keep practicing until you KNOW you’ll do well in the class. </p>
<p>All you need is to build that confidence. </p>
<p>I don’t have the exact link at the moment but Google the MIT classroom videos. Those help a lot too.</p>