I'm making every commercial decision myself and falling behind
Payments, changes, records and the budget are each asking for attention while you are also trying to build a house.
What's happening?
Each decision has a sensible moment: a payment before it is made, a change before it is built, and a site fact on the day it happens. When one person is carrying all of them alongside work, family and site decisions, the routine tends to become a series of catch-ups. By then the information needed for a clear decision is harder to assemble.
This is not solved by one more spreadsheet alone. The commercial side needs a repeating routine that connects the budget, requests for payment, changes and site records, so decisions are made from the same current picture rather than from whatever has reached you most recently.
The solution
Put one person in charge of the connected routines that keep the build's money visible.