Sounds pretty uncomfortable! So, if it is a hemorrhoids issue, that could be chronic. How is your diet? How's your bowel movements? Are they loose often? That can be an issue for chronic anal itching. What about yeast overgrowth? Yes, I think you need to see another doctor. What is the specialist of the doctors you've seen or were they general doctors. Do you have any underlying conditions that you know of like diabetes?
Hello~Since this has been going on for so long, I think I would see the proctologist, he/she will probably be able to discern if it is a skin condition or something internal. In the meantime, while waiting to see one, try soaking in a hot bath with either Epsom salts or Aveeno bath, both can have soothing effects on itching.