If it is chemo fog or chemo brain i found a great article on a few simple tips that can help reverse those side effects. But remember, chemo fog is mostly to do with cognitive function like memory etc. If its nausea or fatigue then it might just be another side effect of chemotherapy unrelated to chemo fog.
here is the link.
http://www.cancermind.com/chemo-brain-treatment-help-study/
Hope that helps