I think that doing it on one's own is the only way to achieve discipline. What is the point of self-discipline and self-improvement if you are doing it for anyone else but yourself? The idea of being able to go into a program where someone turns you into a better person is very attractive, but that is not realistic. It is not easy, and no one else could ever do it for you. Think about high school. Did you put in all of your effort and become a highly disciplined person just because you were expected to get passing grades? I don't think that anyone will ever make true, lasting changes to their life unless they are doing it for themselves, and not because of outside pressure. And what if you had a significant amount of outside help in achieving these goals? What would you do if that source of help were to leave you? It needs to come from within in order for it to be a true life change. That being said, achieving discipline on your own does not have to be a solitary activity, shut off from the rest of the world. Outside support from people you trust is not only helpful, but will provide you with an outside observer who can help you mark your progress. But no, I don't think that these outside forces will or should be the motivating factor in your self-improvement goals.
"On one's own" and "for oneself" are different fields, and I'm not touching upon the latter. Yours and BumpinGumps' views seem to collide. Shall we extract Higgs bosons from it?