I will not be able to give you any advice but I know there are a lot of different kinds of lump
and very different causes. So, now that we know the exact location... it would be good to know the size and what it feels like. Having had a hard "lump behind
", same location, all my life, I was wondering whether you may have had that lump
for a long time and only discovered it now due to the sinus infection pains?