It's very tough to try to balance everything. I know, because my senior year in High School I was working AND going to college as well. Our High School had a college program where we could take a couple of college classes at our Community College. I succeeded, but got only C's due to how overwhelming it was, and I was never a C person.

I think you'll do just fine the second time around, now you know what to expect. Not sure about quitting your job, but if you're financially stable then it wouldn't be a bad idea. I am not so I could never quit my job even when college starts back up in September.

Good luck!