Talent and effort doesn't always translate into passion. From last year's posts where you were worried about crashing and relaxing in a tight paceline to your latest posts where you raised concerns over motivation, it seems like you just don't "love" cycling at his level. And at the level you were riding at, it seems that having passion for the sport is a prerequisite.
As a footnote, as a fan, I must confess that the doping scandals have caused me to lose a lot of passion for the sport as well. When Floyd Landis left South Central Pa, he was a goofy naive hick that just loved to ride his bike, he's not that guy anymore, and that's a shame. And the story of the cancer survivor that came back to beat the world is a much more complicated tale.
I actually saw Breaking Away for the 10th time last week, but first time in many years. There is that scene after the Italians knock him off his bike where he comes back to his room and rips down his cycling posters, that is almost the perfect example of the conflict between our romantic dreams and reality. If you haven't seen it, it is a great film. He gains redemption not by beating the European racers but by accepting who he is.
As a final note, you will always have your time playing in the big leaugues. Never forget that you actually did what us armchair guys always think, "I wonder if I could hang with the studs in Europe." Good luck. I am sure that this is not an easy time for you. But wait till you see how much easier it is to earn a living off the bike than on.