Want to see where you are hitting the wall? Take everything on your to-do list, estimate the time to complete, then schedule on your calendar right there next to all your meetings and commute times.
How does it look? Are you overbooked? Double-booked? Triple-booked?
An accountant might call this exercise reconciling accounts.
A psychologist might call it reconciling cognitive dissonance.
The big airlines can afford to overbook their flights. The rest of us really do not have that luxury and should not act like we do.