Die-off Reaction or Just Tired?

I have been taking the antibiotic Zithromax for a week now. For the first few days, I did not notice any change in my health. Three days into treatment, I developed a bad headache that lasted for 48 hours. I assume that the Lyme bacteria are starting to die and that I am actually experiencing a "die off" reaction. The bacteria are releasing toxins into my body as they die. I am also starting to feel more fatigued. I woke up today feeling awful. My fatigue is so severe that I feel uncomfortable and I can barely get out of bed. I hope that I am experiencing a "die off" reaction because that would mean that the bacteria are starting to die. My fear is that I have been too busy and pushed my body too hard over the last week and that is the cause of my increased fatigue. Hopefully, time will demonstrate for me which scenario I am experiencing.