Thanks for the query.
You might have developed furuncle
These are deep bacterial infections.
You are correct, it might appear due to ingrown hair.
Treatment is with antibiotics but the choice of antibiotics should be based on culture and sensitivity tests.
Please meet a dermatologist
for exact diagnosis.
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.