Jools Lebron's being mindful of her mental health ... telling her faithful followers TikTok's no longer very demure -- and she's stepping away for now.

Here's the deal ... the influencer took to social media recently to talk about her dental issues -- revealing to fans her teeth are literally rotting because of past substance abuse issues.

Jools asked fans for money to help offset the costs and set up a GoFundMe for them to donate ... and, as you can imagine, she got raked over the coals for daring to ask for help during a time of economic hardship for many across the United States.

So Jools took to social media again to call the whole thing off ... telling fans she canceled the GoFundMe and donors would be getting every dollar back.

Jools then went on a rant about the "hive mind" of TikTok ... and, in the post's caption, said she may have to "officially let TikTok go" -- because believing she will ever have the momentum of the "Very Demure" craze on the social media platform again is just ludicrous.

Looks like TikTok's not a very demure social media site anymore ... end of an era!