Fasting

I wonder if anyone can help, I was diagnosed with ER and HER2 positive breast cancer, no spread in nodes, so fab… a friend of mine has recommended fasting for 48 hours before chemo and on the day of chemo… I mean that’s 36hrs of no food!!! Im not sure I can manage it ?
I have had my first herceptin IV and 2 lots of Paclitaxel, small side effects of fatigue and the odd day of nausea but nothing major. Also treatment is preventative and not to reduce Tumors as they