Your College is not a technical school
Why don't companies ever hire me?
From the articles above, Ramit nailed it on the spot, why your grades don't really matter when you apply for work. Yes, it matters a lot on your first job, but after that, most companies look for experience.
Of course, having good grades is still important, since it will measure how good you did with your job as a college student (taken as an experience). However, it won't fair much if you also work while still in college. Being a working student offers you a lot of experience, insight in terms of time management, discipline, technical skills, opportunity and network.
And best, start your own business. Start something, failing and learning is the best experience you will ever get. I for one will always prefer someone who tried to do something and failed, then learned from that experience.