Hello,
Welcome to ehealthforum and thanks for writing
Since the mammo and uSG has been normal so according to the description it seems like an enlarged lymph node which is quite common.Relax and take the treatment as advised ny your treating doctor.There are some things which might help in easing pain as:
1)Application of a hot compress to the affected breast. Soak a towel in castor oil and place it on the area that is affected. Keep this towel in place for about an hour for maximum results. You could also use plain castor oil to regularly massage your breasts. The application of castor oil mixed with essential oils or herbs is also regarded as an effective natural remedy.
2)Use of ginger tea is also popular when it comes to natural remedies for pain relief.
If there is no relief consider visiting your treating Physician for evaluation.
Take care!