Tamar Braxton's BF Says She Was Angry with Network Before Apparent Suicide Attempt

Tamar Braxton was seething mad with her TV network bosses leading up to her apparent suicide attempt -- that's what her boyfriend claimed during his 911 call.

According to the recorded call Tamar's boyfriend, David Adefeso, explained to the dispatcher ... the singer had been having trouble with WeTV -- and he explained how the issues came to a head before last Thursday before he found her unresponsive in their hotel room.

According to David's 911 call -- made Thursday night from the Ritz Carlton in downtown L.A. -- Tamar also left a note before her apparent attempt to take her own life, and he claims she was mixing alcohol with medication she uses to treat anxiety and depression.

Tamar's reality show, "Braxton Family Values," airs on WeTV and she's reportedly been upset with producers for using her childhood trauma -- alleged assaults and rape -- to boost ratings.

As we reported ... EMTs found Tamar unconscious inside her room when they arrived, and she was rushed to the hospital. She's since improved to stable condition.