Johnny Manziel's Dad: My Son's a Druggie ... He Belongs in Jail

Johnny Manziel's father has thrown in the towel on saving his son ... saying if he doesn't get locked up soon ... he'll probably die.

Paul Manziel told ESPN, "He's a druggie. It's not a secret that he's a druggie."

Manziel's father realizes his son's wealth is driving his addiction, and says, "there are two things that are going to happen: He's either going to die, or he's going to figure out that he needs help. But we've done everything that we can do."

Paul has addressed his son's addiction in the past ... but after the former QB's attorney accidentally sent a text message to the media discussing drug habits ... Dad clearly had it.