Should I Be Worried About The Small Painful Lump On The Back Of The Ear?

hello, i have a sister that passed away that she had a small lump behind her right ear that started it. and it went big like a samll ball on the side of her back and right side of her neck doctor said it was cancer i went home before she died and ask her what started it. She normally had bad sinus for years and one day she felt a small like pimple on the right side of the back of her ears. i am pretty scared cause i tooked the benardryl 1 and halp pills and i felt some kind of pressure on the back of my ears. so after few days my allergy attact again so i took the same amount of benadryl tablet. and that night it woke me up that the back of my right ear was really hurting and next day i felt a small pimple size and this is the 2nd day and feeling that it is a little bit bigger than yesterday. Is there anything i have to worry about it? thank you so much...