How long does it take for a non bleeding anal fissure to heal (2 months till date)? Burning sensation/irritation come and go for a few hours every day. Symptoms seem to have improved but not gone fully

About a month. With the help of prescription compounded Nitroglycerin cream or Nifedipine cream they typically heal within a month. Ask your dr for a prescription, and get some relief!
Anal fissure. Sitz baths can help. Sit in the tub for 20-30 minutes at least twice a day. Apply a Lidocaine ointment after the bath. Also make sure you are on a non constipating diet which contains lots of fiber.If after treatment you are not improving see a gastroenterologist to rule out an irritable bowel syndrome.