hello and welcome to HCM forum,
according to the dental history presented by you, it seems a case of chronic infection, you have not mentioned the tooth or the nature of pain if present.
i cannot rule out the diagnosis until checked clinically, but i would definitely like to inform you that your tooth needs to be treated.
infection which is present for quite long , keeps spreading to the sorrounding bone which holds the tooth in position, and resorbs it, this is why you noticed a small perforation or a hole on your gum.
kindly visit a dentist
soon, he/she will click an X-ray to rule out the diagnosis.
i would recommend you maintain your oral hygiene
as you are and meet your dentist.
i wish you good health.