hi..thanks for your query.
From the pattern of eruptions you describe,i feel might have Herpes Simplex
or as you mention cold sores. This is an infection of the lips, mouth, or gums due a virus. It causes small, painful blisters
commonly also called fever blisters.They usually appear within 1-3 weeks after you come into contact with the virus.
symptoms preceding eruptions include:Itching,burning or tingling of the lips or skin around mouth.
Symptoms may go away on their own without treatment in 1 to 2 weeks.Antiviral medicine can be prescribed. It can help reduce pain and make your symptoms go away sooner. Medicines used to treat mouth sores include:Acyclovir
,Valacyclovir.These medicines work best if you take them when you have warning signs of a mouth sore, before any blisters develop.
You have not mentioned the clinical features or what remedy you have used.However i suggest you visit a dermatologist
to get a correct diagnosis and prescription of meds required.
hope this is helpful..take care!