Hole on the left cheek

Patient: Hi..I am Rahul from delhi. I had acne problem in the past but now its gone thanx to my skin specialist.The problrm i am having is that i am having some sort of hole on my left cheek(may be bcoz of acne).I didn’t took it seriously in the past bcoz it’s size was small but now it increases a bit and i am worried it increases more.My doc told me to apply Hexilak gel on it which i am twice a day but it’s been a month and it remains as it is..plz tell me what it is and what i can do ??