I am going to provide a subjective, anecdotal opinion based strictly upon my own experiences.
While you might regard yourself as more an introvert (strictly an assumption), if you aren't able to generate the energy and motivation to put 10-15+ hours per week of dedicated Calculus studying, then my suggestion is to seek out a few classmates (or even just one) and set-up a weekly schedule routine so that you both hold one another accountable, you both help one another to understand things and you have another person who you can bounce ideas off of. In fact, I am getting ready to leave to meet one of my study group for Calculus (I simply asked people in the class if they wanted to start a study group - you'd be surprised how many other people feel the same way you do and simply need another person to work with).
Calculus isn't just mindlessly manipulating symbols on the page. If you have a solid mastery of basic algebraic arithmetic and trigonometry, then you really just need to focus on deeply understanding the concepts and start asking questions. Obviously, there are times you will need to learn and memorize new equations, properties and formulas, but even then, it's best to understand what they mean so that you know why you are doing certain manipulations.
Now, don't take my statement to mean that you should understand every proof and every theorem in your textbook (save that for an Analysis class) but at least intuitively, you need to understand what's going on even if you cannot formally define or prove it to be true.
And again, having another person to talk to can often provide a difficult subject with exceptional clarity.
Good luck my dude!