Everything you do does not suck, even though it can feel that way. Having an adjustable plan of attack and destination will keep you from hanging out in the float. Write a mission statement of who you are and what you want to do with art. Now that you have a path, start your journey!
Critique yourself often but be gently but firm in your observations. Understand that art is not Pass/Fail. You have to know why something passes your test of good or bad. In this podcast, Matt Hodel talks about how he breaks down his illustrations to remove the awkward moments in his work.