Struggling In College

So I've been struggling in college since my freshmen year. I'm about to be a junior and I already change my major twice but I just found out that I will need to retake some classes because I made a D in them. I do horrible on tests and I never make more than a C on my tests. I don't know what else to do. I go to tutoring, study everyday, pay attention and ask questions but nothing helps. Any suggestions?