Lumpectomy or mastectomy?

I have just been diagnosed with invasive carcinoma grade 1,  small (about 1) at 2 0’clock and have to decide pretty quickly whether to have just a lumpectomy or mastectomy. I am terrified of radiotherapy or chemotherapy and terrified of the risk of recurrence. I’m early 40s with young children. I’m leaning towards a mastectomy for those reasons, but surgeons have advised that initial indications suggest a lumpectomy with radiotherapy will be sufficient.  Have spoken to plastic and a mastectomy and reconstruction is possible though obviously major and multiple surgeries. Lumpectomy is simpler but feels like so much risk and unknowns. I don’t know how I’ll make this decision.