Ariana Madix is finally speaking out since calling things off with Tom Sandoval after discovering he'd been having an affair with Raquel Leviss ... and she's leaving an ominous warning -- for Tom.
The "Vanderpump Rules" star shared her thoughts Wednesday night -- first, thanking everyone for the "outpouring of love and support i have received from friends, family, and people i’ve never even met in the last two weeks."
She goes on to call this time in her life her darkest hours, adding "to say i have been devastated and broken is an understatement" ... but she's grateful to have a killer support system as she trudges through it.
She ends with a clear warning -- "What doesn't kill me better run" ... which almost undeniably suggests payback.
It's been a whirlwind in the 'VR' family for a couple weeks -- Tom and Raquel have already apologized for the cheating scandal, and Ariana escaped the noise by going to Mexico.
She went south for a wedding in Oaxaca over the weekend and returned to L.A. Monday ... likely preparing to resume filming for the show's reunion -- but sources close to production told us ... Raquel might be a no-show.