Depression setting in

I'm not doing good in my ecology class or biology. I am in college and have high hopes for ecology. But I'm a creative/English/writer. My goal is to save the earth— I'm a zero waste hippie who wants to get plastics out of the ocean. What should I do? I want my college courses to really impact my career for the better. My shittiness at community college and my classes has me very discouraged from even completing the semester. I seriously don't know what will make me happy. Help. Is there a happy medium somewhere?