I feel so crummy :(

I fasted on apple and cucumber juice for 2 1/2 days. On the third day I started the Liver Flush regimen. However, being 19 I push everything back two hours (no way I can fall asleep at 10, lol). This morning however, I feel way too fatigued. I didn't get any stones, perhaps some tiny pebbles. But I feel really awful and I think my blood pressure is super low (diarrhea does NOT help). I think I'm going to eat now, an apple probably. Anyone have any advice? Does anyone know why I'm so worn out from this?

Btw, this is my second flush. My first one was about 6 months ago, and also didn't yield any stones.