Ariana Grande is lashing out at anyone who thinks Mac Miller's car wreck and DUI is somehow her fault because, as she puts it ... she's NOT his mother or his babysitter.
Ariana responded to one Twitter troll in particular ... saying she had cared for Mac and tried to support his sobriety for years, "But shaming/blaming women for a man's inability to keep his s**t together is a very major problem."
Mac has talked about his struggles with the bottle in the past, and Ariana says it was definitely an issue while they dated. She says, "Of course I didn't share about how hard or scary it was while it was happening but it was."
TMZ broke the story ... Mac smashed up his G-Wagon, and got busted for DUI ... one week after he and Ariana announced their split.
She says she'll continue praying for Mac to figure out his problems, but adds ... it's absurd to expect any woman to "stay in a toxic relationship" just because Mac wrote a song ("Cinderella") about her.