Hi and thanks for the query,
if its swollen and painful its certainly infected. The commonest cause of infection should be due to Staphylococcus
bacteria. Treatment involves using antibiotics and analgesics to calm the pain. T\The antibiotic has to properly chosen and given for a good period of time. The choice and duration of treatment shall depend on the clinical appreciation of your family care physician.
If not properly treated, complication such as systemic invasion of blood that could lead to septicemias might occur. Also there might indicate pus collection, which might require an incision or culture and sensitivity tests.
I suggest you consult your family care physician for reevaluation and follow up,