Okay, so I just wrote a huge post on how ket does not solve problems, so I'm not gonna write it again. However, to sum it up, even though it'll make things better for a while, it'll fuck things up really fast. I find it difficult to believe that anyone's depression is completely untreatable, regardless of what you're told. Plus, speaking from experience, taking ketamine when you're depressed to make yourself feel better is such a terrible idea - you get so used to the reward and relief that it gives you, that it consumes your life incredibly quickly. Think about that before you do this. Do you really want the long term effects on your health? I can assure you, they alone make depression considerably worse. You may feel really awful right now, and you probably don't feel like you particularly care about the effect it will have on you, but a few months into ketamine abuse I can guarantee you'll feel a lot worse.
Talking therapies, medications and various other ways of dealing with debilitating depression aren't easy, and they don't offer the same quick fix, but they're better for your mind and body in the long run. I really, really strongly advise against you doing this, even though you will do it anyway. I destroyed my life, and my body, as did many of my friends, for the sake of trying to relieve depression. Now we're all paying the price, and it's a long uphill struggle. If I'd have dealt with my problems in the first place I wouldn't be struggling so much now.