Um...So...How Do I Follow My Heart?
Start small. You don't want to just drop your current job in exchange for doing what you love—that is, unless you really like challenges. Sometimes getting a jump start on something with no safety net is just the poke in the butt you need to get going on that thing you always wanted to do. For the more timid and cautious at heart, though, you might want to start out by figuring out what it is you want to do. Dream big. If you could do anything, if money were no object, what would you do?
Now, take baby steps towards moving toward that dream. If you want to be an activist, start volunteering. Get involved in causes that are important to you. If you want a Ph.D., study for the GRE, research schools, and apply. If you want to work with foster kids, find out what's required for licensing in your state. No matter what you've been told, whether you've come to believe that you need to make money and you can't do that following your passion, or what your perceived limitations are, if you take one step toward your goal each day, you will reach your goal. The only way you truly fail is by not trying.
If you want to go to graduate school and you can't sleep because you're thinking about it, then do it. If you want to go to law school and you dream of being the next Ally McBeal, Elle Woods, Perry Mason, or Matlock, then do it. The only person who knows what is best for you, what you would be truly gifted at, is you.
So, what would you do if you could do anything you wanted as your career? What is the first step you can take toward that dream?