About 5 weeks ago, I had a cold which lasted around 3-4 days. I took no medication and it went away by itself. However, the cough from the cold has not went away, and I still cough at regular intervals now. In addition to this, I found a small lump in my neck (pea size, maybe smaller), around 2-3 inches above my collarbone, near the centre of the neck, but slightly to the left. The lump appears to only be attached to the skin above it, as I can pinch the skin around it and move it around freely.
After doing quite a bit of research on the internet, I have left myself very worried about potential conditions I could possibly have, including cancers such as thyroid cancer and lymphoma.
From what I can tell, the only symptoms I have are the lump and the persistent cough.
Can anyone give any advise on what they think this may be? I am extremely worried.
If it helps, I am a 17 year old male.