Hi, Welcome to HCM.
The dark pigmentation near your lips is known as Post Inflammatory Hyperpigmentation/ Post Inflammatory Hypermelanosis
(PIH). It is a condition of the skin arising from trauma ( of any nature) to the skin resulting healing with pigmentation.
In your case the cause could have been due to Perioral dermatitis- a condition arising in young adult females due to many a cause but frequent licking of lips is common one.
For your dark pigmentation you can use azelaic acid cream or Kojic acid
cream or glycolic acid
cream or licorice extract or arbutine creams at night time in guidance of dermatologist
Other than that you should apply sunscreen daily half an hour before you are going out and reapplication in 3-4 hours if you are continuously in sun for long hours.
Most importantly you should not even touch your affected area as you have had history of removing skin from the wound as can cause persistent pigmentation.
In between you can use good concealers which can mask the acute effect of pigmentation.
Hope to have better of skin with this advice,
Dr Sanjay K Kanodia