Where do your structural flaws exist? What makes you shake in your boots? Self-introspect these matters, and then seek a reasonable resolution. If you have a trusted trainer, go to them and pick their brain for answers. If it is an overwhelming fear, definitely seek their advice. You must remember that your response to an incident may affect other officers' lives or other third parties' lives. If you have a fear that's riddling your life, then seek professional help.
Small worries are one thing and they can be dealt with a trainer or FTO. If you're worried about choking in court on your first case, your FTO will drill you prior to court. If you're bugged about not completing the FTO program on schedule, the FTO sergeant will sit down with you to evaluate your progress.
Worried about the boogie man who jumps out at you with blazing guns and a made-for-the-movies shoot-out? Get to your trainers and talk this out about tactics and realistic application of your responses in traffic stops or building checks.
Is there a monster under your bed? Nope, you're just going through what every young officer goes through in your transition to Copland. It's doable; we all have done it and you will as well.
Trust your trainers and FTOs and believe in yourself. The ability to meet challenges comes from within you; it is not bought at the store. Believe in yourself as a winner!