I understand and agree with some of what Vi-Rainbow said. I mean, you put yourself out there and push yourself to the extremes, and sometimes your efforts don't have any effect, and you get fed up and throw in the towel.
BUT.
Your course of action depends on how much you value your friendship, and your friend, GamblingGambit. Genuine friendships don't happen over night. A person's true colours only come out when they are being challenged. Your friend is obviously being challenged on emotional levels. You are being challenged, too. Are you going to step up to the plate and do whatever it takes to help your friend? If you're going to back out halfway into the deal, rather not try help him at all. He'll resent you for it. Trust me, I'm talking from experience - and no, I wasn't the one doing the helping, I was the one in a hellhole.
So, basically, everybody needs that ONE person who would stick to them, no matter what. Who won't judge them, or cast them aside, or give up on them, come what may. You need to evaluate yourself first and really ask the question - do you care about him enough? How much? Enough to not turn your back when he throws your kindness back in your face? Enough to take a bullet for him, if it came down to it? If you don't, just have your say and leave him be. If you DO, the only way you'll be able to help him is by sticking on his side through every single step of hell he has to endure and brings upon himself. Lecturing doesn't help, believe me. I'm not saying you should start doing everything he does, you need to stay strong in that aspect, but just hang with him. Let him know you're there. Sooner or later, he's going to realize you're the only one that hasn't abandoned him, and he'll come around enough to actually ask you for help. It might take a while, but you'll eventually get there.
Hope that helps, if any.