NEVER break a fast on a low! You are definitely detoxing, and breaking your fast will only extend the crisis. Fast through, drink LOTS of extra water, and keep your colon VERY clean (I have had a plain water enema stop many a detox crisis dead in its tracks)!
You can always look at a crisis as flushing out the bad stuff. The body is letting you know it needed this cleanse! If you can fast through til you are up again, and do a good solid break (by the book), you will be giving yourself a truly wonderful Christmas present!