Why am I having breast tenderness years after lumpectomy?

I was diagnosed 2022 lcis breast cancer stage one. Lumpectomy 11/22 and I have been on three meds, anastrozole, tamoxifen now exemastene. I had had five breast biopsies, two uterine biopsies and one hysteroscopy D&C, which is the reason I went off tamoxifen. I need two knee replacements and I’m great shape but my bones and joints are Tami g a beating. I now have some tendernesss where my surgery was and I need an ultrasound. To say I am devastated in an understatement. The fear of going though this again makes me cry. My oncologist said, oh it is probably scar tissue, seems odd three and a half years later. Anyone been through this?