Nothing is daunting as waiting in expectation for something. It is even worse when you have no idea of how and at what time it would come.
Waiting on God to provide the answer to your requests equally applies to some of the ways you wait for ordinary things to happen. Rather than sitting without doing nothing, I propose you simply trust Him knowing that He has heard you.
He says at the appointed time. That means at His time, and not yours. Therefore, praise Him continually while doing the waiting, and don’t give up.