Itchy sinus with swollen lymph node

For the past few days, I\'ve been having some mysterious symptoms. Starting this Thursday, I noticed a swollen lymph node on the right side of my neck, behind my ear and jawbone. It was sore to the touch. The next day, it was still swollen but not sore anymore, but my shoulder on that side was sore and my sinus next to my nose was itchy, like it\'s an infection and it\'s spreading. Today I was really tired and spent most of the day sleeping. It\'s still swollen and not sore. Last night my mom gave me some medicine because she thought it might be a cold or something, but that only seemed to make it worse. I could feel it swell into my throat and my sinus got more itchy. I don\'t know what this is but I did some research and I think it is an infection. I won\'t be able to go to the doctor\'s for a couple days though. Do you know what this is? Is it serious?
P.S. I\'m a 14 year old girl, turning 15 in August if that helps at all...