I can not say that I have any good recommendations, other than try looking at some of the ingredients of things that you eat on your "free" days. The more natural the diet, and the more ingredients that are in it that your body is used to, the easier it is for your body to break things down. Your body has become unfamiliar with things that you may have cut out, or cut back on, such as hydrogenated oils, complex sugars, red meats, whatever you have cut back on, that it just does not know what to do with them. As a result, you feel bloated, sick to your stomach, lethargic...

I'm not sure if that helps at all. Hope you are still having a decent day.