I think part of the issue with the self-help approach is that it's trying to solve a problem that results from changes that are systematic and fundamental to the way humans live, and thus which need to be solved at the level of civilization, not the level of the individual.
In other words, individuals can mitigate the effects of these structural changes for themselves, but probably not ultimately resolve them.
While our shift to more or less utilitarian principles and capitalism has yielded large gains in increased production and higher quality of life, we've lost a great majority of the social structures, practices, and institutions that used to infuse life with meaning.
I've been reading a great deal about this recently in the work of Georges Bataille--when you contrast archaic forms of civilization with our own, some of the differences are striking--while we have much better living conditions, our ancestor's lives were generally much richer in structures that produce meaning (ritual, religion, monarchy, family, village...), and I think humanity is still struggling with their loss. Batialle points out how the biblical phrase "man does not live by bread alone" is really a truism about humanity, whether or not you're religious.
Replace "bread" with "material" and you largely have uncovered the problems of modern society--if you examine your familial and personal relationships you'll recognize that, subversively, so many of them are still attached to the acquisition and expenditure of material and are necessarily subordinate to economic mechanisms, and that pretty much all of man's meaning today is reducible to some form of accumulation, quantity, and possession (i.e. getting 'likes' on facebook--even in the digital world, the metaphor is material and centers around accumulation of a phony resource). Man desires sovereignty, but when he reduces himself to nothing more than a means (i.e. a thing that produces and acquires) and builds all his relationships around this principle, he doesn't actually share in any sovereignty--he makes a mechanism of himself.
I think this sort of dynamic is at the root of a lot of contemporary individual unhappiness.
If you take your time with it, reading philosophy will often yield many insights that I find help one not only grow as a person, but better understand one's being in the world. Actually, philosophy was really the original form of self-help for the ancients--only more effective, because it had attendant belief systems and thus was a set of practices suffuse with meaning (i.e. isms, stoicism, platonism, etc.--self-help books generally don't provide an 'ism' and ultimately don't provide a framework for maneuvering through the world, but rather provide ad hoc techniques which crumble quickly when not predicated on an underlying system for understanding phenomena). Old philosophical self-help wasn't merely a collection of tips on how to make your way through capitalist, isolating, hyper-technical systems without offing yourself--which is really what most (NOTE: NOT ALL) 'self-help' amounts to.