I can't say I'm in a position to really give some advice to you.
I never went to college, mostly because I felt I was never intellectually prepared (Still don't think I am), but also because I feared I too would want to quit, since I never quite meshed well with traditional education (Dropped out of High School). Not having the funds to do it also kinda put a monkey wrench in it. I would have studied Philosophy or Physics (Or both), and you can't do much with those without going all the way and competing with people who put their lives into it, or going to some other field, so college never made much sense to me.
But if went, I would have pushed myself until I finished it, no matter what happened (I know this contradicts my fear, but if that much money is on the line, I'm going to get SOMETHING out of it). I would have probably been in a lot of debt with only a meager GPA to show for it and no reasonable prospect of employment, but I would have done it, and goddamnit would I have been proud of myself, because I'm usually a forward looking guy (When I'm not ridiculously pessimistic and overly cautious, which are two things that, bad enough as they are together, are even worse when you alternate between them, as I've had the displeasure of discovering), and also because I wouldn't allow myself to feel down about it. No one in my family has ever gone to college. We're all poor folk, and the idea of college and "moving on up" is an endearing one well worth chasing, even if the chase is better than the actual reward.
I personally don't know if it's a good idea for you to quit or not, since only you know what's going on and what's a good idea in your circumstances, but if I were in your shoes (with just the minor adjustments of my choice in major and the likes), I would stay.