Lizzo is once again batting off haters who have nothing but mean things to say about her -- but this time, it's truly gotten to her ... 'cause she's in tears on camera.

The singer went live Sunday and broke down over what she says is growing negativity aimed in her direction following the release of her and Cardi B's new song, "Rumors," which Lizzo says amounts to fat-shaming, racism and accusations of catering to white audiences.

Lizzo says that despite trying to put positive energy in the world through her music or posts or whatever, she feels like she oftentimes receives more hatred back than love ... and while she notes that she's got thick skin for that type of thing, it's weighing on her hard now.

She makes a valid point -- namely, that if you're not into her music or persona or anything else about her artistry, just change the dial to something else ... instead, however, Lizzo says she's been noticing people going out of their way to belittle her, and she can't make sense of it.

This is nothing new for her -- Lizzo's dealt with this type of hate since splashing onto the scene, and she's usually pretty good about telling people to kick rocks. She ends doing that here as well, but this video is truly a peek at how hard all the trash-talking is hitting her armor ... and heartbreaking, to say the least. Even Cardi felt compelled to speak up.

She writes, "When you stand up for yourself they claim your problematic & sensitive. When you don’t they tear you apart until you crying like this. Whether you skinny,big,plastic, they going to always try to put their insecurities on you. Remember these are nerds looking at the popular table." Other celebs have come to her defense as well, including Chloe Bailey.

Lizzo says she's going to start focusing on the positive and ignore hate messages she might read about herself on social media and elsewhere -- TBH, that sounds like a great idea.