1. Detoxing = I swear you will get the feeling of being high without smoking as your body flushes it out. Smoking + flushing = panic attack from being way too high.
2. You have anxiety now due to a toxic level of THC perhaps
3. It could cover up extreme nausea or dangerous symptoms that are a signal to break fast for health
4. No additional herbs etc should be taken on a fast because of organ strain.
I suggest waiting a couple days AT LEAST if not a couple weeks after your fast to start smoking again. When you break fast you will be sensitive to certain foods that are bad for you and your need for them will be naturally turned off preventing sickness. If you are smoking you could end up sick because your body's signals are not allowed to come through unfiltered.
Plus your anxiety will be a lot lower after detoxing. You may only need valerian tea instead.