The nervous system is one of Lyme and Co's main targets. The myelin sheath covering the nerves is often damaged during the bug attack and that's what can cause those internal vibrations, stinging/burning and shock-type sensations....along with tingling and numbness.
It's possible that something you eat or drink could exacerbate the symptoms - especially if whatever you consume stimulates the immune system.
On page 293 of his new coinfections book that includes Bartonella, Buhner writes : "It is not uncommon for the sensory and neurological systems to become exceptionally sensitive to any kind of external input."
Whether the symptoms are a herx or "just" another symptom likely depends on whether or not you had these issues before starting treatment. If you had them before, I'd consider them a symptom. If they developed after you started treatment, then I'd consider them to be a herx.
No matter what the cause, increasing your detox can only help and you might want to consider taking things that help the nervous system.
In his books, Buhner lists a variety of herbs that can help with these issues. Buhner says that all of the herbs he recommends can be used with all of the herbs used in all other herbal protocols.
Here's a link to his (now outdated) site that lists a couple of herbs that can help:
buhnerhealinglyme.com/lyme/neuropathy/Buhner also mentions the benefits of NAC (N-acetylcysteine) supplementation in his newer coinfection book that addresses Bartonella: It "has strong protective effects against neurotoxicity throughout the CNS" and it "acts throughout the entire peripheral nervous system to inhibit inflammation".
Conquering nerve issues has been my main focus throughout treatment because my PNS (peripheral nervous system) has been most affected by these bugs.
There is a bunch of stuff you can do to help with these issues but it does take time for them to resolve.