Suggest Treatment For Swelling On Vagina

hello doc, i have a red walnut shaped swell on the outer lips of my vagina.....its very very painful...atfirst it was small one...but then it grew itchy so i scratched it and now its a long swollen one...i have been using an imidazole containing ointment...but its not working...plzz help...i am also having my monthly periods so the situation is getting worst....plus i have my sem final exams....please atleast suggest me a painkiller.. :(