After reading most of the other posts in this thread, I concur with most of them. Just keep training. Do shadow boxing exercises. Do light-contact sparring exercises (but do NOT pull your punches, take the hits!) and like some have already said, practice slow at first. Work only on your defense. Body movements, blocking, footwork, break it all down and practice each one individually. Then once you get comfortable with defense, fire back! Start working on your counters and offense. Then once you get really good at countering, eliminate your defense altogether and work on intercepting the opponent and attacking him first.