what do I do?

I am a freshman in college, and I am about to finish my first year of college. I want to go to med school and I am freaking out. I feel like a failure because I think I am going to fail my Biology class with a ( D maybe?) I also have another D in one of my classes. Besides these two I have an A in two of my other classes(AADD). I had 2 B’s and a C last semester. What do I do? Should I give up on science?