Slight fever, runny nose, found a small bump on the back of neck?

I think I have the flu. I have had a fever on and off since yesterday. It first started with sinus drainage and then I got a sore throat. Then felt nauseated and tired. When I got home from work I didn't really have an appetite and went to sleep. Today I felt a tad better during the day but in the evening my fever is coming back, I had chills earlier and I still have the sore throat. I have a runny and congested nose. also. I know my neck has been sore and I was feeling the back and felt a small bump on the back of the left side of my neck. I don't know if it's something I should be concerned about or not. I know you can get swollen lymph nodes. It feels sore when I put pressure on it. I break out sometimes, but never on my neck so I wouldn't think it would be a pimple. Any advice?