Just take it easy and stop over-analyzing your days. You will have up and down days. Many of us have 25% days then 75% days and consistently ride the roller coaster of PCS. The long phone calls and hours on the computer can be exhausting. You do not necessarily feel the symptoms during the task. They may show up a bit later or not until the next day.

It is not uncommon to feel "wiped out" by dinner time even without the hours of phone calls. Get off the phone. Limit your computer time to ten minute sessions. Multiple ten minute sessions spread over the day will be better tolerated.

Listen to you body/brain. It knows best.