Hi i do care for your concern. The lump in your anal region may be an infected abscess as the size increase and so the pain. It is more common for infectious lump to occur in the region, mostly of bacterial origin. I would suggest To consult your physician and to know the nature of the lump, and if abscess then drainage of the abscess may be required. To continue antibiotics along with antacid for five days will completely resolve the symptoms. hope the condition resolves soon. Hope i have answered your question, if you have more feel free to ask. Thank you.