How to discover one's calling in life?

Maybe my calling is not defined in communication arts. Maybe I am called to be a doctor, I just don't have money for a medical education. How do you explain that? Then, maybe i'll just be a businessman, with MBA, Masters in Entrepreneurship, Economics, Marketing or Financial engineering. Should I confine my happiness with what my money could afford? I guess not. It should not be. But I should at least learn how to earn a living and I gotta try everyday. I just got to. If there would be no food for the table, I would just market my accounting services. Sell a few items. I need to make money. Or maybe I can just go for my dreams and be a struggling writer or hit it big time with billiards. I guess what's stopping me is the what ifs. When you are growing older you tend to have analysis-paralysis and you just keep on wondering of the whys and the hows and not just do it unlike when you were young. At 34, I am very happy. My life is incomplete in so many ways, but I know I am very happy and everyday I work on what I think God has given me as assignments in this life. At the end of my life, I will be very happy to be welcomed by God and say to Him that I have done everything I can to the best of my abilities no matter how many mistakes I may have committed by trying to achieve what He wants me to achieve and because of that I knew I did His will. Some more dreams.. want to study law but I figured I have difficulty in reading law texts, still I want to study law even if I don't become a lawyer but once I finish law I know I am gonna be a lawyer, I just know that! Study medicine, if I have the money, study MBA and Masters in Entrepreneurship, Masters in Computer Science or Information Technology. Of course, i am not gonna study all of those. Just 2 or 3. Study cars and airplanes. Cooking, interior design, fashion design, photography and filmmaking. Then, I am complete.