I am a sophomore in college and I went through something similar. What I did was prioritize. Write down everything you do for a week, so every 15 minutes or so to see what takes up the most time. For me it was the internet (facebook, etc) and organizations. After that see what you can cut out or multitask doing. Such as getting dinner and studying, or you could even do it with a friend who is in the same class which takes care of three things.

Do not think it is the end of the world if you get one bad grade that will make it worse. I am on scholarships as well, and at my school if you drop below a 3.0 for one semester you get another semester to see if you can get it up, your school may have something similar. Best of luck