A few days ago I noticed a painless, movable swollen lymph node on the lower left side of my neck near my collarbone. I started worrying about lymphoma then since I had a cough. After taking medicine for chest and lung congestion, my cough went away and I stopped worrying about it. Today I found out that a painless swollen lymph node near the collarbone is a sign of a cancerous condition. I've been freaking out for the last few hours. I can't concentrate on anything, I just keep thinking about this. It's actually slightly smaller than it was yesterday but I'm still worried about this. I need help.