Selena Gomez is opening up even more about her struggles with bipolar disorder … revealing she had suicidal thoughts and checked into 4 different treatment centers.

She says, “I think when I started hitting my early twenties is when it started to get really dark, when I started to feel like I was not in control of what I was feeling, whether that was really great or really bad.”

In the Rolling Stone interview, Selena also recounts having extreme highs and lows for weeks or months, before understanding her bipolar diagnosis. At times she would have symptoms of mania like feeling the need to buy everyone in her life a car so she could share her “gift” — but then she’d fall into a deep state of depression and not be able to get out of bed.

And in her darkest moments, she said … “I thought the world would be better if I wasn’t there.” After a 2018 episode, she says she ended up on a ton of meds, which helped her psychosis, but made her feel unlike herself.

She also touched on all the fan-stirred drama, where fans accused Hailey Bieber of stealing her ex, Justin Bieber … saying it made her feel bad about herself.

In the past, she says this kinda incident could’ve set her back for months … but this time it was diffused with kindness.

You’ll recall, Selena and Hailey posed with each other last month at an event — seemingly putting the whole mess behind them.

Selena gives a deeper look into her life in her new doc “Selena Gomez: My Mind & Me.” It premiered Wednesday night in L.A. … and stars such as Olivia Rodrigo, Camila Cabello and Billie Eilish were all in attendance.

The documentary is out on Apple TV+ tomorrow.

If you or someone you know is thinking of suicide, please call the National Suicide Prevention Lifeline at 988.