Blemish on lower left of penis head [nsfw]

I'm not sure what this is, but it seemed to show up with pain. About 30 days ago, a girl who has HSV2 but did not have an active outbreak kissed my ear and neck. About a week ago, this spot showed up with pain as it came.

I have experienced what I thought were other symptoms but have since come to realize they were probably anxiety induced hypochondria. Hoping this is some sort of zipper scratch or something else. Can anyone please ease my thoughts?

Image for the brave [nsfw]: http://imgur.com/8os5Dpy