Tactics are take each day at a time and don't worry about tomorrow or the next day or next week. I am 10 days post my 3rd chemo and I walked the dogs this morning, albeit nice and slow and cycled up to the local shop, also snail pace but I managed.
For my first chemo my white blood cells plummeted to zero which showed up on the 10 days after blood test. Now, they send me home with a neulasta injection which I give myself in the belly fat so my body actually makes white cells and doesn't make me spend a whole 3 weeks in virtual zombie mode.