Breast Cancer Forum - Terrified This Is Breast Cancer

I am a 47 year old female. Grandmother had breast cancer in her 70's; no other history in family. I have yearly mamograms and have had microcalcifications removed from right breast 13 years ago; benign. My current mamogram revealed a 4.6mm nodule with borders not entirely defined, containing a few microcalcification (4-6). Not seen on ultrasound. The report indicated it was suggestive of an intramammary lymph node with calcification, however, since the finding was new, biopsy was recommended. Birads 4b. I am absolutely terrified. I have seen a surgeon and basically they cannot tell me what it is. The nodule is in the tail of the breast so I am not a candidate for core needle biopsy because it is hard to reach. My pcp said the radiologist was not overly concerned and did not mention it was likely to be cancer. I have an anxiety disorder and am absolutely convinced that I have cancer that has spread all over my body. I will follow up with the surgical biopsy. My question is - is there any way this nodule could be benign? They did not mention my intramammory lymph nodes were enlarged and my breast exam was normal. If it is a cancer, does it sound like something that was caught early? There is no palpable lump. Sorry for the long question; I am absolutely going out of my mind. I search the internet constantly and always seem to find something that convinces me I have metastatic cancer. I cannot concentrate and am convinced I do not have long to live. I have consulted my psychiatrist who puts things into perspective for me when I am talking to him, however, the panic and terror return shortly after. Please shed some light on this for me.
Thank you.