What should i do if i keep getting fired?

I have a degree in Finance. I have held four careers all related to the field and have gotten fired from each of them due to "not meeting expectations of the company" and "poor performance" and none of which my former employers would go into detail about. For all of these companies, I feel as though I did everything correct and on time. My only guesses as to why I'm getting fired a lot is that I ask a lot of questions, I'm a slow learner, and might have taken longer than the average person to complete the task. I'm about ready to give up and look for any old job that will pay the bills, possibly a company not even looking for someone with a college degree. What does everyone else think? Please be honest. I won't be hurt hearing that I should just settle for a job and not a career.