It could just be a cyst, but always good to have it looked at. Keep us posted.
Hard, painful lump could result from an injury, infection, cyst or fibrocystic change. If you had previous breast injuries, fat cells in the breast tissue may be damaged and produce a firm, painful lump in the breast. If lumps are accompanied by breast tenderness and redness, it may suggest an infection. Similarly, breast cysts can also produce firm, tender lumps in the breast that change in size and seem to appear and disappear as your monthly hormone levels change. They often cause pain before your period is due and improve when the period starts. Lastly, fibrocystic changes appear as lumps with irregular borders and grainy texture.
I suggest that you see your surgeon or gynecologist to evaluate your lump. Your doctor may perform an ultrasound, MRI, mammography or biopsy, depending on the character of the lumps observed during manual breast examination.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Definitely follow up whenever you can, was thinking about you :)