I am often asked what it means to "herx" or to be herxing. Here are some explanations I found online. Basically it is a worsening of symptoms due to the antibiotics doing their job & killing off the bacteria. The die off of the bacteria causes your body to become "toxic". The kidneys & liver can only do so much to detox you, so I must drink a lot of water, & take hot baths to make myself sweat. If the herx makes me feel nauseous, I take activated charcoal. That seems to help.
It's hard to tell the difference between regular lyme sypmtoms & a herx. So herxing is good. If indeed that is what it is. But your doc does not want you to herx "hard" because it further weakens the immune system.
This is hard to watch. If my treatment now stops working, this is what I have to look forward to. Mine have never been this bad.