Breast cancer with possible spread to lymph nodes in neck

Hi, I have been really worried. Last year I was diagnosed with BC Her2+ and I had chemo Fec-T and radiotherapy. I started zolendronic acid on Friday and I am still on Herceptin. Yesterday I went for an ultrasound to my neck. The radiologist spoke of finding 3 enlarged lymph nodes I think at the base of my neck. I am so worried it has come back and that prognosis will be poor. Has anyone had anything similar? IN other ways I am feeling well. Thank you. Xx