Simply Exhausted

Hi there, I could use some advice. I started a Water Fast on November 1st. I had read alot of information on Water Fasting and what to expect. After the first 3-4 days, I felt energized and had a feeling of freedom of food. I have continued this way until yesterday evening. Yesterday evening, it was as though I was giving a tons of bricks to lug around with me and I noticed a rash around my hairline. Normally my skin is very clear. This morning it was difficult to get out of bed and I was restless during the night -- for the first time in weeks I had a bowel movement which was very water and dark. I've coughed up phlegm and I have a slight headache and pain in my neck. What do these signs mean? Is it a healing crisis? Am I causing damage to my body now? Should I be ending my fast now, I was planning on 21 days or longer -- it is day 16 now?

Appreciate the advice.