It IS okay to set threelac aside for a few days. Die- off is ALWAYS about you wanting to go TOO fast and not letting you body adjust progressively to the new treatment.
Don't stop to drastically either , slow down (one dose every second day?) listen to your body and once you feel better slowly augment the doses.
Sorry to hear that you are so tired. You shouls also take note of what you have been eating, as tiredness might be a sign of intolerance (allergy) to what you have eaten or to perfume/detergent.
MOre on die-off below: