Not an expert on oil pulling but here is my thought: is your sunflower oil cold pressed? or refined? do try oil pulling with other kind of oil and see - i've heard about virgin coconut oil which has good results.
for me any other vegetable oil than coconut worsten the bacteria load in my mouth.change the oil to see...some bacteria and some strains of fungus could easily feed on oils also if that is your prblem
in my country some try propolis on the gums or local application with herbal powder with sage, calendula...might work