Hi, I Have Been Suffering From Anal Itch In Soon

Hi,
I have been suffering from anal itch in soon two years. I have seen doctors. Most recently I was told that I had a rash and got timodine, which so far has just increased the itch, but made the swelling go down. However, the rash came long after the itching began and probably because I have been self-treating with antibacterial cream. I am rather desperate and getting tired of symptom treatment. The main itch is just on the inside of the anus and it is not haemorrhoids. Please help. Many thanks in advance