Rory Feek is being confronted with having to say goodbye to his beloved wife, Joey, but he'll have a very special song to remember her by after she has gone.

In a new post to his blog, This Life I Live, the Joey + Rory singer says Joey — who has been battling Stage 4 cancer since June — has been deteriorating over the last few days.

"I’d like to tell you that she’s doing great and is going to beat this thing," he writes. "But I can’t."

Rory recalls a song titled "When I'm Gone," which he and his wife recorded for their His & Hers album in 2012. Their friend Sandy Lawrence wrote the poignant tune as a way of dealing with her own emotions as she was caring for her dying mother, and when the duo heard it, they had such a powerful reaction, they knew they wanted to include it.

Joey sang lead on the track, which is written from the perspective of someone who's dying, who's trying to reassure the loved ones they leave behind that they'll be okay after they're gone. When the couple shot the video, the director suggested Joey sing the song to her husband on film — an idea he resisted.

"It hit too close to home," he admits, but he ultimately realized the idea was right for the song. "I realized that “yes, of course. We have to make it that way. It’s the story in the song,'" he says. "It wasn’t what I wanted… but it’s what the song wanted.  And though it scared me for us to be that vulnerable, it was also what our whole lives and music career was about – being real… being honest."

"And so the cameras rolled and both Joey and I let us ourselves imagine what it would be like if she had to leave this world and I was left behind without her…And now here I sit beside my dying wife," he writes soberly.

"I don’t say those words lightly.  As a matter-of-fact, I haven’t said them at all.  But my beautiful bride has said them to me in these couple of days. Her pain and discomfort has continued to increase daily and so has the morphine to help her be comfortable. The dosage she’s needed to keep the pain away has quadrupled in the last four days."

The singer reflects that the song seems to be coming true before his eyes. "Some call it ‘life imitating art.' I don't," he writes. "I call it God. He knew I would need her to tell me goodbye… not just once, but a thousand times. And I’d need to know that no matter how much time passes, that she loves me still. And He made it so that if I needed to be reminded of her beautiful life and heart and voice… she would only be a ‘click’ away."

Rory adds that he's not angry at the irony of the song.

"How many men who are losing the woman they love get a gift like that?" he asks. "None that I know of."

In fact, he and Joey have decided to include the song on their upcoming album, Hymns That Are Important to Us, which is set for release in a few weeks.

"It’s not a classic hymn, but to us it is," he notes. "It is a very special song, filled with hope and love. And in time, I believe it will have the power to help heal a million broken hearts…

"Even mine."

In November, fans launched an online campaign to get "When I'm Gone" to No. 1 on iTunes. Purchase the song at iTunes by clicking this link.

See Joey + Rory's Cutest Pictures Through the Years

Learn More About Joey Feek's Cancer Battle

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