My opinion is that it would be OK to stop with the little aches and pains that you are having. It may take longer for these issues to detox themselves out once you start breaking, but your attitude sounds good, and I think that's the most important thing.
The book says that you can also break with grapefruit juice, so maybe that's an option. I've used lemonade during my break. I actually craved the stuff - can you imagine? That's all I was allowed to have for days on end, then when I'm allowed to have something else, I wanted lemonade!! :)
Next time you plan on doing the cleanse, order your syrup online. I just bought from this site (http://store.valuenutrition.com/index.html) and got a half-gallon for 15.63!! And if you spend $100, you get free shipping.