Joey + Rory have been incredibly lucky to have family, friends and fans by their side during Joey Feek's battle with terminal cancer, and in a new blog post, Rory Feek gives thanks for another one of them: their manager, Aaron Carnahan.

Feb. 5, 2016, marks Carnahan's 48th birthday -- and because he and Rory Feek are cousins (Feek's mother and Carnahan's father are siblings), they've known each other for all of those 48 years. "We grew up separately, together," Feek writes. During hard times for Feek's family, his cousin was always there.

"During our high school years, Aaron spent dozens of nights camped out beside me on the living room floor in our little house … through one particular winter when we had no heat and had to hang blankets over the doorways, because we also had no doors," Feek recalls. "It didn’t matter to him that just across town his family had a nice warm home and his room had a heated waterbed."

Feek and Carnahan have seen numerous parallels in their lives as they've grown up as well: Both married, had two daughters and got divorced; both have children with Down syndrome (Greg Carnahan, Aaron's third child, is 25; Indiana Feek, Rory's third child, is almost two); and both became Christians later in life.

"His second marriage to Jill Hodel was the vision of marriage that I had always hoped for and dreamed of. So beside my bed each night, I prayed that God might bring someone special into my life, like He had brought to Aaron," Rory Feek shares. "Not long after that, I was playing a show at the Bluebird Cafe, and a beautiful brown-eyed girl with a boy’s name was in the audience listening. Joey and I got married in 2002" -- and the two couples even share a wedding anniversary.

In a strange twist of fate, Joey Feek and Jill Carnahan share some characteristics: They both grew up in farmhouses, Feek in Indiana and Carnahan in Illinois, and both have four siblings, all with "J" names. They have also both fought cancer; fortunately, Carnahan has made a full recovery.

"When I called Aaron in May of 2014 and told him that the doctors suspected that Joey had a tumor on her cervix … he couldn’t take any more," Rory Feek recounts. "I remember him crying on the phone and saying … 'you can’t have this. This is where it has to stop…' That was the one place where the paralleling of our lives was almost too much for him to bare."

Aaron Carnahan was also the one whose encouragement -- and the fact that he pushed his cousin and his wife to audition -- led Joey + Rory to CMT's Can You Duet. He officially became their manager, despite his lack of music business and artist management experience, in 2012.

"Looking back now, it’s easy to see that Aaron was helping guide our career, long before he was ever managing us," Rory Feek muses. "... He had no experience in the music business, no experience managing an artist and knew no one in Nashville really, except us. But what he had was faith. And a belief that anything is possible. Coupled with a desire to help us reach our goals while living an honest and authentic life together.

"What we’ve been able to accomplish since Aaron started working with us had been nothing short of amazing," Feek continues. "Though he is technically our manager, he doesn’t really manage us or our career. Not really. He just loves us."

Feek praises his cousin, noting that Carnahan "works tirelessly on our behalf" and "has babysat, mowed our lawn, painted barns, fixed broken sewer lines, grocery shopped, killed skunks, weeded our garden, cleaned our house and a million other big and small things that have nothing to do with his job -- all to help make our dreams come true and our lives better." The "man of many, many hats" is with Joey + Rory more often than he is home in Colorado.

"And now, here we are in 2016, and Aaron’s still managing … us … our music … and where life has led us. But mostly, I think he’s just doing his best to manage the pain he feels. He wants so desperately to fix this for us, but he knows he can’t," Rory Feek says. "... I think he’s cried more tears over what is happening right now than all of us put together ... There isn’t a moment that goes by that we aren’t thankful for him and all he’s done for us and with us."

Joey + Rory's Sweetest Pictures

Unforgettable Joey + Rory Songs

More From TheBoot