Have you ever overpromised on some work you were doing for someone else?
Augustine did that when he promised to preach 1 John in a certain amount of time. Things probably started fine, but as he was going along he realized his plan was no good. So at the end of sermon number six of what would become a ten-part series, he tells his listeners, “I am afraid the epistle itself will not be finished during these days as I promised, but as the Lord will, it is better to reserve the remainder, than to overload your hearts with too much food”.
Everyone makes planning mistakes, even Augustine. When you do, follow his example.
Instead of barreling forward, be humble. Keep your priorities straight, readjust as necessary, and let everyone know what’s going on.