Should I be concerned about this...?

I have had the flu for the past 5 days. My tonsils started swelling really bad, and I had trouble breathing so I got Amoxicillin and the swelling went down but then my nose started to get really congested and running. Then yesterday, it moved into my lungs and they are really hot and I am coughing really wet. But what I am wondering about is that under my chin (where I think a gland is) it is really really sore and swollen. I was wondering if I should be concerned about this. Please Help. Thank you.