Ariana Grande thanked her fans "for everything" as she said farewell to a challenging 2018 on Monday (31Dec18).

The Thank U, Next hitmaker has had a tough year due to her short-lived engagement to Saturday Night Live comedian Pete Davidson, which was called off in October (18), a month after the shock death of her ex-boyfriend Mac Miller.

As 2018 came to a close on Monday, Ariana celebrated the occasion by thanking her fans for their support and looking ahead to 2019.

"Farewell 2018, you f**k," she wrote on Instagram. "I hope this new year brings you all much laughter, clarity and healing. be gentle with yourselves and each other. if we made it thru this last year, we’ll for sure make it thru this one. thank you for everything."

When she accepted the Woman of the Year honour at the Billboard Women in Music Awards earlier in December, the 25-year-old fought back tears when she said 2018 had been "one of the worst years in my life" even though it had been one of her best professionally, with Thank U, Next giving her her first-ever U.S. number one single.

"As far as my personal life goes I really have no idea what the f**k I am doing," she said. "So yeah, it's been a very conflicting one. I just want to say if you're someone out there who has no idea what this next chapter is going to bring, you're not alone in that."

Ariana had been due to celebrate the New Year by performing in Las Vegas on Saturday, but she had to cancel due to health issues, which has been reported as bronchitis.

Over the weekend, Ariana also shared a throwback photo of Mac playing the piano on her Instagram Stories and debuted the latest addition to her extensive tattoo collection, the words "Let's sing" written in Japanese etched on her upper right arm.