Thanks for query,
It seems that you are having fissure in ano
with severe infection.
Go for antibiotic and anti inflammatory medicine for 3-5 days.
Take laxative at night so that you pass your stool smoothly helping healing fissure.
Avoid fried,chillies and junk food.
Take plenty of water.
Apply some local analgesic
If there is no relief then you have to go for surgery.
Ok and bye.