Rose took to Instagram to share the message along with a photo of the "Fancy" singer, 26, surrounded by flowers in her dressing room.
"My heart goes out to you @thenewclassic I have been through heartbreak as well so I know what you are going through. Stay strong and keep your head up my Rosebuds and I support you and we think ur AMAZING!!
"I remember watching ur YouTube videos a few years back thinking 'Wow this girl is gonna be a star' and you are! Let all the hate go in one ear and out the other... Trust me I deal with just as much hate if not more," she wrote.
"... Date a bunch of hot guys and give yourself some new cool options #NoCuffingSeason," Rose wrote.
Azalea and NBA player Young, 31, broke off their engagement in late June.