The presence of lump over the collarbone can be due to:
to bone or soft tissue
in that region
2. Infected cyst
Investigation like X ray
will be helpful in clinching the diagnosis.
Though symptomatic relief can be obtained by intake of analgesics, it will be better to consult your General Physician once & get a proper examination done to find out the exact cause.
Based on that, appropriate management steps could be taken.
Wishing you a good health.
Thanks & take care.