Changing majors and credits/grades

So I came into college as a kinesiology, knowing that I might change majors. Two of my classes are related to kinesiology, so if I change majors is it commonplace to lose those credits? Also, I got a 4.0 in three of my classes, but a 1.5 in one of my kinesiology classes. Is that grade going to affect me if I change majors? Should I be stressing about it?

You keep all credits (and their effect on GPA), but the courses may only be applicable to general education requirements or (at worst) free elective credits if they are not applicable to the subject requirements of your new major.