(I Circumcised) Hello, For About 2 Months Now, I Have

(I circumcised) Hello, for about 2 months now, I have had a hole on the underside of my penis. At first it was small, but now it has grown to about 0.2 cm. It is starting to hurt, as well as worry me. I believe it is caused by irritation from masturbation, and do not know how to stop it. Please help me figure out how I can get this hole to heal, as well as how to prevent this from happening in the future. Do I need to stop masturbating? If so, for how long? Must I have to visit my doctor?