1. Bold of you to assume I'm a "she."
2. If other people want to eat lunch, fine, schedule yourself a lunch break. That's my point, there's so much more utility when we set our own schedules. People eat in class all the time. And "in the middle of the week" is precisely the problem. Why have it Wednesday and not Friday? Three day weekends? See where I'm going here?
I'd cancel if I were you, especially because of your GPA. I have a GPA that is on the lower side as well and I basically think anything below 165 is useless to me. I'm aiming for 169+. But if you have a school that you think will accept a 3.0 and 156 then of course don't cancel. But if you don't know of any school that will accept that (I don't know if there are any), then just cancel it and get the free retake. Why waste money on keeping a score that's worthless?