I have a very itchy rash on my left palm. i have had it for about 6 months, my doctor just told me by looking at it, that it is herpes, is that possible?

Unlikely: Herpes would not be present for 6 months. I would suspect contact dermatitis from continually touching something. But yes herpes can be diagnosed by simply looking at the lesions.

Unlikely: It's possible, but it would be very unusual for herpes to stick around for 6 months. Herpes usually gets better on its own, and then may come back again later in the same place.