Selma, die-off lasted far more than a couple of weeks, but a true herxheimer reaction lasted for a couple of weeks when I first stated antibiotics: I was delirious and feverish amongst other things.
Lyme disease is probably different in reactions to C pn which is what I had. I never had any pain, which is typical of early lyme.
People on the Cpn protocol often have worse reactions than me but never, so far as know, get on a downward spiral from which they don't recover.
Have you tried melatonin for sleep issues? There is a large section about it on my husband's site: it is very good and totally non-addictive:
If you can get to sleep you might end up feeling able to try antibiotics, because if you have lyme disease that is the only way to properly get rid of it.