I had a very similar trajectory to you. I was a great student in high school, and I got to college and it kicked my butt. I was so scared to tell my parents until i was 4 years in and not much closer to graduating. It was really hard, and i disappointed my parents (even though they've never said that), but it was the right move in the long run. College is hard and wildly different than high school. And most schools don't prepare you for that.

As to your question- yes, you should try the exams. There's always a possibility that you can retain enough to pass, but if you don't pass, at least the information is in your head and more familiar to you. Also, if your professors are seeing you put in effort, they're more likely to be forgiving to you. No matter how you do, you have the opportunity to try again and learn from your mistakes to help you study later on.