Welcome to the board.
Cardio is usually good when limited to 30 minutes or less per day. More than that and you can start to break down your lean mass. Are you doing your cardio your lifting?
No idea regarding the headaches, I've only experienced a few samples of drive/rpm. I loved them, but I didn't notice a headache.
It's usually a good idea to cycle most products, drive/rpm are no exceptions. I'd recommending searching the board but I'll wager a guess of about 4 to 6 weeks followed by 2 weeks off or something similar to that.
If you're looking at gaining size, supplement with food, lots of food. Another product that would be relatively inexpensive would include a form of creatine.
As it stands right now I'd just stick with the drive/rpm. Work on your college diet and get in ample amounts of protien throughout the day.