Loss of identity

Compared to other people posting on here mine sounds churlish. I had breast excision 3rd December and awaiting results tomorrow for treatment plan hopefully just radiotherapy and medication. I have done really well emotionally but lost it yesterday. Feeling sorry for myself and a loss of identity. I was told to concentrate on me and self dare but I’m feeling surplus to requirements-will I have a meaningful role to return to at work as they seem to have coped without me for 3 weeks. How do I fit in the family? My son had already offered to host Christmas prior to my diagnosis but I feel I have been replaced. How do people cope with emotions? Should I speak to a professional or is this just the norm for new cancer diagnosis