The vets will likely tell you that this is a "classic cleansing crisis".
The nay-sayers will say "what the hell did you expect? you haven't eaten for 16 days".
I tend to fall somewhere in the middle. If I were experiencing blackouts I'd have called it quits then and there. It's kind of hard to experience all the wonderful benefits of this cleanse if your dead or laying up in a hospital somewhere because you passed out on the road and crashed.
Maybe your body was trying to tell you it was done and ready for you stop. If you haven't gotten sick from the burrito yet, you probably wont. Just be mindful of what yo eat for the next week or so. Your body is going to try and hold onto whatever you give it!