The First Time I Noticed This Lump Behind My Left

The first time I noticed this lump behind my left ear about a year and a half ago, I asked my PCP about it. He said it's not something for me to worry about, and asked him twice about it. He did not even look and check it, instead, he just said it's not cancer. Lately, it's been bothering me a lot because of the pain and it seems like it's getting bigger in size. How do I go about getting an answer to my concerns.