I don't think anyone's going to argue that the placebo effect and psychosomatic responses in general isn't among the craziest mind-bending stuff in medical science. That said...
there are plenty of people who have convinced themselves so thoroughly that sugar pills cure cancer that their cancer has actually gone away.
Citation needed I'm not taking your word for it, because I've got no reason to believe you're qualified, or a qualified person's word for it unless they've also got a history of publishing things that aren't crazy.
More importantly...
The (personal) problem I have with this exultation of mind-over-matter is it diminishes the very real possibility that something very real is wrong. For a trivial example, willpower won't set bones, reattach ligaments, or anything of the sort. Although people are surprisingly good at making themselves sick just by thinking about it, the same doesn't apply to healing themselves or even undoing their own psychosomatic damage.
EDIT:
What I mean to say is that when you say stuff like that, I consider you a low grade environmental hazard. Like an automobile, or an evening of binge drinking.