Chyna's Manager -- I Struck Deal with 'Intervention' Show ... Days Before Death

Chyna's manager tells TMZ Sports ... he had recently struck a secret deal with the producers of the TV show "Intervention" to get Chyna help ... but she died before they could start production.

We spoke with Anthony Anzaldo ... who tells us Chyna's closest friends had become concerned about her prescription drug use in recent weeks -- worried that she was over-medicating herself with Ambien and Valium. He's adamant Chyna's issue was ONLY with Rx meds.

Anzaldo says he entered into talks with "Intervention" producers about doing an episode with Chyna -- in the hopes they could get her back on the right path before it was too late.

We're told an agreement was reached -- and the plan was to get a bunch of Chyna's closest WWE friends, including Stone Cold Steve Austin and Mick Foley, to participate in the intervention.

"An interventionalist was already lined up as was a facility that was going to take her for 90 days," Anzaldo says. We reached out to "Intervention" -- so far, no word back.

Anzaldo says he became concerned when he hadn't heard from Chyna in days and went to her Redondo Beach apartment to check in on Wednesday evening.

"I found her," Anzaldo says ... noting that he believes she died in her sleep. "She looked peaceful."

As for the future, Anzaldo says he's planning a huge memorial for Chyna -- with celebs and fans ... hoping to give Chyna the send-off she deserved.