@Nix,
Its so early for you. You are still in a state of shock. Nothing you did made this happen. There are people who ate clean, did yoga, never drank who still got it.
Having said that if you have chemo you may find yourself in a situation where eating anything can be tricky. I was told to eat what i felt like. What i pyschologically felt like was healthy eating. What i could actually eat sometimes varied. Be kind to yourself.
Diet can have a big impact on how you feel which is super important. After i did 4 cycles chemo treatment of AC I sought a dietician to help me feel as good as possible through the remaining chemo. It did help a great deal with fatigue and when o came out of chemo having looked after my diet and done a little exercise i quickly started to feel good.
Ive just finished radiotherapy and fatigue levels arent too bad but i feel terrible and have had to cut some slack in diet as i cant manage food at present.
I choose not to drink alcohol mainly because ive drank so much water over my treatment and when hydration was not good enough i feel terrible. Alcohol can be quite dehydrating.
Always be kind to yourself. Dont be too restrictive. Best of luck.
Michele