IS Career?

Does being good at something or having the ability to do something well necessarily mean that you should pursue that as a career? Even though you might not like it with a passion! I feel like that is what makes me wishy/washy when it comes to finalizing my major and its exact focus. I've had the opportunity to try different types of courses and the outcome has always been: I like it, but don't receive an awesome grade or I'm not fascinated with the criteria but I do tend to perform fairly well in the course. In other words, what is stopping me from following a IS career or an accounting career? And why am I pursuing a career in economics? Oh buddy.. Decisions, decisions..