She said she's happy I'm off of tamoxifen now. Both hormone receptors were negative per the Caris results she saw, which is why she wanted me off of it.
In summary, it's likely I didn't have a genetic pre-disposition to breast cancer. I begged her for some answers. I said "is there ANY recommendations you can make so I don't have to go through this again?" She said keep your weight down, be fit, avoid sugars, and take lots of vitamin D (2000 iu's a day). I feel like these are all things that I do already, and did before I had cancer. So... hoping for the best!