I have an itch inside my (urethra) that refuses to go away.I have seen a urologist without success?

This itch is infrequent but occurs a few times a week and its only inside the head of my . Feels like a quick twinge or tickle. Doesn't hurt but its incredibly annoying. I have seen 4 doctors and they have given me antibiotics although I was told there was nothing wrong with me and I probably didnt need them. After numerous urine tests and even a painful swab test I was told there is not wrong with me. I'm very frustrated and I know its not a mental thing , I feel this itch and its annoying. I am married as well. My wife shares my frustration.Im scared I'll always have this problem, the doctors have no answers. Please help.