Correct.
If, in fact, it is a sebaceous cyst or cellulitis then the suggestions here for acne would actually worsen the condition by promoting bacterial growth. Both of those conditions are indicated by your description in addition to acne.
If you did see a dermatologist, and she said it was an ingrown hair follicle, then she probably gave you aftercare treatment advice. If this advice isn’t working then it’s likely she’s diagnosing by reaction to the prescribed treatment, in which case she needs to know the results. Call her office and tell her what is happening, and be sure to include the new symptoms of pain and irritation.