Please start exercising again. You need it. Your body likes it. Your heart likes it...the emotional and the physical one.
The fact that you have not gained weight due to replacing meals with coffee is not a reason not to exercise.
The result of the coffee running through your veins is that you cannot sleep at night.
The result of not being able to go to sleep at night is that you don't get up on time.
The result of not getting up on time is that your morning is rushed and although a Larabar and an apple is a good once-in-awhile breakfast, the fact that you are eating it at 10am every day is not the best.
Now, finish your homework, drive home, and go to bed. Someone [and by someone I mean a cat because you are on the periphery of being a crazy cat lady] wants to cuddle with you. You can dream about boys. You can snuggle in your awesome bed. You can wear sweatpants.