B"H! I am wondering whether there is a source for the following story or if there is a story similar to it in a Midrash or another text? There was a rabbi who had a wife that he loved dearly, but she died. He grieved over her intensely until he withdrew into his house and locked himself in, hidden from everyone. A woman heard about him and went to him, saying, "I need to ask you something. Nothing will satisfy me except what you say about it." He said, "Ask." The woman asked him, "I borrowed a piece of jewellery from a neighbour of mine, and I used it for a long time. Then they asked for it to be returned. Should I return it?" The rabbi said, "Yes." She said, "But I have had it for a long time." The rabbi said, "It is better for you to return it to them, since they lent it to you." She said, "Exactly! Why do you grieve over what Hashem lent you and then took away from you, when He has a greater right to it than you?" The rabbi saw the situation he was in, and Hashem helped him by her words.

Our sages (Midrash Mishlei (Buber) 31) relate the story regarding R. Meir and his son- or 2 sons (not wife) who died, and his wife Bruria gave him a similar parable to that which you mentioned.