Thanks for the query.
You might have developed an infected cyst
THIS NEEDS TO BE DRAINED SURGICALLY,
Along with this oral as well as topical antibiotics are must.
The choice of antibiotic can be best based on culture and sensitivity.
Please meet a dermatologist
and discuss regarding this.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.