Hi Penny,
I totally understand how you feel - walking into the unknown is so stressful! I tend to agree with your oncologist who says to eat as normal - not more, not less, eat what makes you feel good! Some people say, however, to avoid the foods you really love during chemo because you might develop an aversion to them. That didn't happen to me, although there is one chicken soup recipe that I haven't been able to have almost a year out because I associate it with being sick (I would eat it when I had nausea). I also drank A LOT of water because I just normally do, and my chemo nurse said it might have helped with dealing with some of the side effects.
Listen to your body and to your needs. If you feel like eating healthy, do so, but don't feel stressed out if you're not eating superfoods at every meal! The days after AC chemo I would have almost a pound of bacon per day for breakfast, eggs, poutine, so much junk food because that's all that made me feel good. The important thing to remember is that you have to eat something, anything because your body will need the energy to rebuild itself.
Another thing that can be helpful dealing with side effects is to exercise, even on chemo days. I would go for runs on Taxol days and cycle (stationary) on AC days (when I felt well enough). I was told it helps the body deal with the toxins and breakdown products. Anyway, who knows, but I think it helped me physically and mentally!
I don't know if it will help you but my mantra during this whole ordeal has been "Don't worry, nothing's under control". It helped me keep calm, not stress about everything that was out of my control, and approach treatment confidently. Whatever happens, your team will be there for you and you can find help here too.
Finally, I bought this cooking book before treatment. I can't remember doing many of the recipes but they are a good guide as to what foods could be good to help deal with certain side effects:
The Cancer-Fighting Kitchen: Nourishing, Big-Flavor Recipes for Cancer Treatment and Recovery
Good luck Monday. Don't hesitate to post here again if anything. I'm sure everything will go well!