Hi,
Welcome to ehealthforum,
It is difficult to comment on the cause for the bump in the side of neck that you describe without examining you and going ahead with further evaluation. It could include be due to lymph node swelling/inflammation. The exact cause can only be made out after careful evaluation (it will also rule out chances of pre-cancerous or cancerous changes). You should consider visiting your doctor/healthcare provider at the earliest for thorough examination and further evaluation to look for the underlying cause and determine origin of the bump. Treatment as appropriate (based on examination findings and investigations results) would be started to help you control the symptoms.
Take care.