Not saying anything that anyone else hasn't already said, but: heck no- you don't suck. You're a stud! I admire you for racing- something I'm way too terrified/chicken liver to do. I was asked to do some TTs (and I'm a triathlete for crying out loud- I do TTs all the time) and crits with a friend and I won't do it because it's new and unknown and a bit scary. You have the courage to get out there and do it- so you're a HUGE winner in my book.
You've done so much this last year, you should be VERY pleased with yourself (but I know how easy it is to berate and curse your efforts when you feel they're not where you know you could be).
Just get reacquainted with your bike again on a friendly basis. I sometimes feel bad for people at the top of amateur sports because there's so much pressure to keep performing at a certain level (and winning, and placing and all that). In the middle and back of the pack- I never have to worry about all that pressure. I just have fun and finish when I do. Come- just for a little while- and see how much fun us back of the packers have at rides and races. We're usually the ones who talk and make friends because we're out there for so long together.