While reading the Prologue to Walter Kaufmann's translation of Buber's I and Thou, I stumbled across this interesting little gem: "…Hebrew prophecy wasn't meant to be fulfilled." As one of his examples, he uses Jonah's story. While there are clearly prophecy's which are meant to be fulfilled, it is just as true that many prophecies of doom include an "unless clause." God provides an out because He doesn't want to follow through with the promise of doom.
The grace and patience of God, as Paul tells us, are intended to give us time to come to our senses. The care of God for his creation prompts Him to warn us time and again to return to Him. This is key, as Kaufmann points out. God is more interested in people who want to follow Him than in any particular ritual or religious practice. It isn't always critical to get the details "right," but wanting to follow God is critical – even if we do so imperfectly.
So, give yourself and others a break, and rest in the grace of God.