You have reached a vital point along the path to authentic self liberation: the great divide that exists between what a person knows versus what he or she is capable of doing with that knowledge. As you're beginning to see, anyone can grow flowers while the sun shines; its another story altogether when it comes to acting from the light of what one knows is true to do in moments of darkness. Saint Paul went through this same stage, and he reported on it with words to this effect: "I don't do the good I want to do, instead I do the evil I don't want to do!" So, you see, little comfort though it may be, you're not alone.

The reason that the "truth sets us free" isn't so much because of something that we're able to "do" with it -- with regards to trying to "fix" or control what's wrecking us, or holding us back -- but rather through the always shocking discovery that, as we are at present, there is very little we can do that is real; and by "real" I mean act in such a way that we no longer harm ourselves or others without knowing it. And to paraphrase your question -- "what can I do to get unstuck and stop destroying my own happiness?" -- you've already seen the answer; you just don't want to see the truth of it for fear it means you'll be stuck with some kind of suffering forever.

The only place any of us get stuck is in the world of resistance...of not wanting whatever it may be we fear about our self and its "life". It's very hard to see, but resistance is a form of attachment. But once this understanding dawns in us, as it must if we persist with our wish to be free, we stop fighting with ourselves to become something imagined. This also ends the disappointment we feel over what we have failed to become. Then we begin the real interior work of attending to the "self" that invariably traps itself in a world of its own unconscious wants (and not wants). It is only in dying to this self that we are liberated from doing its bidding; what remains can't act against itself or another.