first of all you will have to get rid of constipation
and hard stool.
take plenty roughage in your diet and have plenty water to drink . use sorbilin 4 tsf in morning in empty stomach.take 2 glass of water.lactulose
30 ml at night ,anobliss ointment may be used internally.
2%gelly if used internally before going to poop will relieve pain
consult surgeon and get definitive treatment for fissure in ano
do not take spicy diet.
hope you recover soon