Welcome to HCM
We understand your concerns
From the description you gave, the lump bove collar bone might be a simple sprain
. The pain around the area and arm pit might be associated with the sprain which happened due to the reason you already mentioned. If the lump is exactly on the throat area, the reason could be tonsils infection, lymph
node enlargement, Slivary glands infection or even mumps
. But these are only possibilities. Also are you in for any treatment for any other chronic problems? Application of olive oil and hot wter fermentation might give you relief. Consult a physician if this persists for more than three days without sign of relief.
Get well soon.