Ditto what Girlie said.
It's not that your symptoms get worse but you can feel worse because of the treatment. The goal of treatment is to kill the bacteria. Bacteria loads vary based on how long you have had the disease and if you have any co infections. Therefore die off varies too. It's refereed to as a herx.
www.lymediseaseblog.com/jarisch-herxheimer-reaction-lyme-disease/The more you detox the better your body handles the herx. Have you adjusted your diet to gluten free, dairy free, sugar free, clean? I know I am missing something else.
Six months is short unless you started on high dose abx's right away.