Hi,
Everytime I've detoxed it's taken me at least a couple of weeks to get my full appetite back but eventually it does come back. I'd say if it doesn't start to return and you are still feeling ill within a week, to see a doctor if possible just in case something else may be wrong. Sometimes these pills can cover up other things that may be wrong with us and we don't realize it until we are off of them. Other times it's just the detox process and it takes a while to return to "normal". I've also lost a lot of weight and hair during detoxes, they do take their toll on us for sure. Congrats on 13 days and hopefully you start to feel better soon :)
I am on day 15 and just starting to feel better in the mornings. I to was waking up sick to my Stomach everyday. As far as appetite try doing some like exercise and it might trigger you hunger at some point during the day. I know if I work out at night I wake up hungry the next morning. Way to go on the 13 days and keep up the good work. You will feel better. It just takes time.