Shawn Mendes is living his best life.
The Grammy Award nominee, who turns 24 on Monday, kicked off his birthday weekend Saturday at LIV Nightclub in Miami, where a source tells PEOPLE he had an "amazing time" partying with The Weeknd during the Dawn FM artist's surprise performance.
"Shawn was in amazing spirits," the insider says, adding that Mendes "looked super happy to be there, relaxed and just enjoying the environment."
He hung out with friends in the DJ booth until The Weeknd, 32, arrived, during which he and DJ Kaytranada joined the artist onstage.
VEM / BACKGRID
Mendes was also photographed showing off his physique as he hit the beach in a pair of red swim trunks. He shared photos on Instagram of himself soaking up some sun with friends on the back of a yacht.
"It has become more clear that I need to take the time I've never taken personally, to ground myself and come back stronger," he wrote in a statement. "I unfortunately have to cancel the rest of the tour dates in North America, and the UK/Europe."
"We were hopeful that I might be able to pick up with the rest of the dates after some much-needed time off, but at this time I have to put my health as my first priority. This doesn't mean I won't be making new music, and I can't wait to see you on tour in the future," Mendes added.
A source told PEOPLE that Mendes is "getting help" for his mental health, explaining: "Shawn is a very sensitive and caring guy."
RELATED VIDEO: Shawn Mendes Calls His Break-up Song Writing "Therapeutic"
"When he gets frustrated with things around him, he turns inward and suffers," the insider added. "He said he is getting help so that is admirable."