Question re Wig and Diet please

Hi there,
I am 42, no kids and have recently been diagnosed with Invasive Ductal Cancer - oestrogen negative, Stage 1.
My op is next week, followed by 4 months chemo and radiotherapy after.
I asked my consultant if there were any changes I needed to make to my diet and he said No. However I have read many articles on the link between Dairy and Breast Cancer. They all seem to refer to when Oestrogen is positive, ie hormone related Breast cancer.
Does anybody know if giving up dairy would be beneficial for my type of cancer? I do consider my Diet to be very balanced, I exercise about 4 times a week, never eat processed food, but I do currently eat meat, dairy, everything really.
Also, I got engaged 2 weeks before finding the lump. I went wig shopping today and was strongly advised towards a Real wig. However many of the threads here advise against. Her point was that I would be able to style it for my wedding. I would love to get married a year after last Treatment, and know my hair won't be back long again.
Any advice?
Thanks in advance :-)
Hartey