What Is The Dosage Of Erthromycin For Abscess Near Wisdom Tooth?

hi i've been prescribed Metronidazole for a abscess over my wisdom tooth together with erythromycin. However, I just remembered that i took this drug (Metronidazole) previously for a different reason and I had extreme lethargy and general feeling of uselessness. I have taken two 400mg tablets of a course of 21 tablets. I want to stop, is it early enough to do so without harm? Will the erythromycin clean up the abcess?