Allow yourself a semester to take several exploratory classes, conduct information interviews, and gather the information you need to reach a satisfying decision. I must choose between having a career and having a family. It is not OK to be undecided because being undecided is a sign of immaturity. Interests do not become firmly established until you are in your mid-20s. Well-defined career interests and direction have more to do with experience than maturity level.
Life is always fair.
Unfortunately, life is not always fair. Dealing with the unfairness of life can teach you the skills necessary to deal with adversity, which is part of the human condition. Life is always unfair. Fortunately, life sometimes is fair. Generally, effort determines outcome, and you have a reasonable amount of control over your career success.