I'm not a doctor but I would definately go see one.
You should see a breast specialist or doctor for your symptoms.
Does the lump increase or decrease in size? Is it painful or tender?
Has a mammogram, ultrasound and MRI been done? What is your age?
Have you noticed any abnormal features on breast self examination like skin changes, breast lump, nipple discharge , etc ?
Till then you could try some warm compresses, breast massage and oral pain relief medications.
Let us know about what your doctor or breast specialist advises.
Let us know if you have any other doubts and also about how you are doing.