Selena Gomez is singing her truth ... the star released a new track called "Anxiety" today, with duet parter and pal Julia Michaels collab'ing.

To give you an idea of the vibe, some of the lyrics go: "I’ve always wanted to be one of those people in the room that says something and everyone puts their hand up / Like, if you’re sad, put your hand up,” Gomez sings in the track. “Feel like I’m always apologizing for feeling / Like I’m out of my mind when I’m doing just fine."

But here's the semi-bombshell ... she seems to reference ex Justin Bieber in this part! "And my exes will say that I’m hard to deal with / And I admit it." Bombshell #2 -- she admits to taking medication for her anxiety issues.

In an Instagram post today announcing the release of the single, Gomez caption and pic of her and Michaels: "This song is extremely close to my heart as I’ve experienced anxiety and know a lot of my friends do too. You’re never alone if you feel this way. The message is much needed and I really hope you guys like it!"