I am sorry to hear that you have a small (5mm) whitish sore on the tip of your tongue, and that you are worried that because of your HSV1 history that it may be related to the herpes virus. I am happy to give you some information about the herpes virus, and oral sores, but ultimately to get the most accurate answer, I would recommend that you make an appointment with an ENT (Ear Nose Throat), or even a dermatologist
that specializes in oral pathology. They will be able to take more of a history, and examine you. They may even perform a culture of the sore, or even a biopsy
(to send some tissue to a pathologist
to evaluate) it it looks concerning. You are correct that HSV1 (Herpes Simplex Virus type 1) can cause oral lesions. Typically herpes oral lesions start out with vesicles (fluid filled blisters) that eventually burst and cause ulcers. So knowing the progression of how the lesion started would give some more information. 'canker sores' typically do not start with blisters, but rather painful ulcers that can be associated with stress, diet, or other deficiencies. Unfortunately other more ominous pathologies (like a cancer) can also present with a painful ulcer. This is all the more reason that it is worthwhile to get evaluated by a physician that is used to dealing with oral pathologies including cancers (like an ENT). Best of luck.