I would add to these 5 tips:
Be kind to yourself.
Stay in bed or on the couch. Don’t feel guilty about not doing laundry or going to work.
Call a friend, hopefully one who listens and gets Lyme. Avoid friends who don’t.
Do maintain your habits including grooming habits: shower, brush your teeth … For me, I feel even worse when there are sweaters on my teeth.
Distract yourself. Watch a movie, read a book, draw. This is actually hard to do when herxing. Sometimes all I could do was count the cracks in the ceiling. It was amusing as I always came up with different counts. Find the humor. And embrace the fear.
Stay positive: Repeat as necessary: “Herxing is not forever. I will feel better soon.”