I'm smart or think but never do well on exams.I get everything is discus in class but never do well on exams?

In my macro class i understand everything the professor talks about. i even relate it to real life and stuff and it seems to be right. when i tell the professor he always takes my examples as good examples to or help the class understand the material better. Bit when ever we have a quiz or an exam i never get better than 70-75 no matter how much i study o understand the material. and, the other thing is that i hate to study alone i never study well if i'm by my self. i really need help and find out what is it that i want in life, cause i dont even know if i still love business. HELP PLEASE