Why 'Despacito' singer Luis Fonsi says his 'best year ever' was also 'heartbreaking'

— -- What does it feel like to have YouTube’s most watched video ever? Just ask Luis Fonsi, the singer who’s behind the year’s breakout song and music video, “Despacito.”

“I didn't believe it,” the 39-year-old told ABC News for the two-hour special “The Year: 2017,” which airs on Dec. 19 at 9 p.m. ET. “And it just kept on growing and growing and it's still like one of the most viewed videos. I'm just so blessed, so honored.”

Fonsi was also nominated for three Grammy awards this year for his first U.S. crossover hit.

“I'm very proud that a Spanish song is nominated for song of the year and for record of the year, two huge categories,” Fonsi said. “It's been 20 years doing this and to be able to have a song that really connects with people at this level, it's really special.”

And with the birth of his son, “I’ve had probably the best year of my life,” he said. But the year has also been a difficult one for his family.

“On a professional level, it has been an amazing year. On a personal level, to see the devastation of my island, it's been heartbreaking. And not only Puerto Rico, but you know what happened in earthquake.htm" id="ramplink_Mexico_" target="_blank">Mexico: my brothers and sisters in Mexico with a bad earthquake,” Fonsi said. “The whole world is sort of upside down a little bit, so I can't fully celebrate everything because I know that there are a lot of people that need my help. But, on the other hand, I'm very thankful and blessed for everything that has happened with my career.”

The music video for “Despacito” was shot in Puerto Rico, where Fonsi and his family are from. La Perla, the Puerto Rican island shown throughout the video, was devastated earlier this year by Hurricane Maria, and many of the beautiful, colorful houses in the video’s backdrop no longer have roofs.

“People just had to move out. It's still [has] no electricity, no running water. So, on one end you're celebrating something. Then you go back, and it's all gone,” Fonsi said.

While Fonsi left Puerto Rico at age 11, many of his family members still live there. He owns a house on the island and considers Puerto Rico home.

“Still, to this day, some of my family still have no electricity. A lot of my friends have lost their jobs. So, it's a place that I love dearly, and it's starting to move forward very slowly but it still needs a lot of help,” said Fonsi.

He has made it his mission to do what he can to help restore normalcy in Puerto Rico. He’s been back since the hurricane, taking planes full of goods and medicine, and doing what he can financially to give aid to his fellow Puerto Ricans.

“We have to keep on going, and it's going to take maybe over a year to get Puerto Rico back on its feet, but I'm going to be there along the way,” Fonsi said.

Fonsi will return again soon to deliver toys for the children.

“If there's one thing about us Puerto Ricans, it’s that we're happy people, and I'm sure that Christmas time -- although it's going to be tough and it's gonna be sad for a lot of people who've lost everything -- they'll figure out a way to sing and dance through it and that's something that I am proud of,” he said. “It is gonna be a tough Christmas, but we're going to be OK.”

Watch ABC News' “The Year: 2017,” which airs on Dec. 19 at 9 p.m. ET.