hi
thanks for question
It is unlikely that you have any problem of collar bone
I might be wrong as I am assuming this without clinical examination based on your symptoms
However in neck there are not a single
lymph node
classically lymph nodes in face and neck are divided into 7 region with 3,4,5 lying in neck
these lymph nodes are connected to each other also via ducts
You have already swollen one lymph node which can happen with any urti,
sinusitis or any other related infection
And these infection could have spread to other nodes leading to infection and inflammation
Resulting in pain and sweelling in neck near clavicle
Do Luke warm water gargle if suffering from urti
Also drink lot of fluids.
And please do visit your physician so that he can clinically examine you and confirm diagnosis
And can prescribe appropriate antibiotics if required