Aside from what everyone else has said, the bottom line is that to be successful in anything you do in your life; you are going to have to be devoted to it. Medicine is difficult. So is becoming the superintendent of a school district, so is becoming a CEO and all those things take many years of hard work and dedication.

You need to do something that you enjoy with your life so that you can be excited about devoting yourself to it. Medicine = excitement to go to class and dissect a person, or learn about autoimmunity. Don't waste your time if you have any thought that it might be a waste to study rather than get plowed through any miserable excuse.