Psalm 13:5 New International Version (NIV)
5 But I trust in your unfailing love;
my heart rejoices in your salvation.
My soul has been feeling weary this week, so my heart has found comfort in another hymn I've known since childhood, "O Love That Will Not Let Me Go." George Matheson, the author, was indeed familiar with heartbreak, This was written of hymn and the genesis of the song as found in Wikipedia:
"I am quite sure that the whole work was completed in five minutes, and equally sure that it never received at my hands any retouching or correction. I have no natural gift of rhythm. All the other verses I have ever written are manufactured articles; this came like a dayspring from on high." 
"O Love That Wilt Not Let Me Go" was written on the evening of Matheson’s sister’s marriage. Years before, he had been engaged, until his fiancée learned that he was going blind—that there was nothing the doctors could do—and she told him that she could not go through life with a blind man. He went blind while studying for the ministry, and his sister had been the one to care for him through the years, but now she was gone. He was now 40, and his sister’s marriage brought a fresh reminder of his own heartbreak. It was in the midst of this circumstance and intense sadness that the Lord gave Matheson this hymn, which he said was written in five minutes.
I'm not sure if there are any other vocal groups that can do justice to a hymn of this sort than the Gaither Vocal Band.
O Love That Will Not Let Me Go [Live]