Breast cancer

Good morning , recently diagnosed with breast cancer grade 2. Had a lump ectomy and 5 lymph nodes removed , now change of  treatment. plan as tumor was double size and 4 lymph nodes where positive, I have to have another operation as margins were not clear and a removal of more lymph there was also talk of  chemo. Now and  a mastectomy ? Head alover. Don’t  know what to do ?