How are you? I'm sorry to hear about the pain in your breasts. Are there other symptoms such as fever, chest pain or swelling? Was there trauma to your breast wihin the past 2 months after your biopsy? After lumpectomy, there is usually little pain. There may be temporary unpleasant sensations, including numbness and a pinching or pulling feeling in the underarm area but this also resolves when the tissue heals. But with this increasing pain, it would be best to call your doctor for proper evaluation.
Take care and keep us posted.
Sounds like it might be due to nerve damage that often happens during surgery. It might be wise to discuss this with your Surgeon and get his/her opinion.