Found Something White On The Foreskin Of Penis. Using Tree Oil. Is It A STD?

I have a something white that grows in the foreskin of me penis on one spot which has not spread to any part of my penis. If I leave it alone for a week, I can remove small parts of the white material if i dig at it with my nail. I think its a fungus infection, I been using tree oil so it wont grow and it helps but it does not go away. I read that tree oil is good for fungus. I have two open wounds now from the tree oil burning my foreskin. IS there something else I can use or do I have an STD. I have not had sex in years so I hope its just a fungus infection. It first appeared after the last time I had sex, I did not wash my penis or took a shower a day after having sex. My dick started to itch and I noticed this white thing growing on it. It went away after a few months, now it came back out of nowhere so i been using tree oil. Should I go to my family doctor or go see a urologist? Any idea what it could be?