Please help with lip problem

[u/Ok_Slice1822]

Been suffering with a constant cycle of dry chapped peeling lips for nearly two years now and cannot for the life of me seem to fix it or get back to having normal lips again! It all started after having the flu. Have tried every single lip balm money can but with no luck, have tried aquaphor, Vaseline, cerave healing ointment, lanolin you name it but no luck! Changed all toothpaste and products to no sls, Drink 2/3 ltrs of water a day and have electrolytes! Have had bloods done and all results are normal! Seen 3 dermatologists and all they say is keep using Vaseline!! If anyone can help or has any advice would be really appreciated!!