Try not to worry, I have little raised lumps and sometimes it itches as well.
I certainly have not got herpes or any other type of std.
It may be worth poping to see your gp just to check it out, they may just give you some cream, or at least put your mind at rest. You may be embrassed for a few mins, but its worth a long time worrying.
If you are in the uk, you could go a local gum clinic, where they deal with all bits to do with down below.
Hth
cathy