Keep at it and you will get there. Just continue to strive to be better and your proficiency at the job will increase.
If after after a considerable amount of time, say 8 months to a year or so, you still feel absolutely incompetent on the job, then you might have to start looking for a new role that plays to your strengths. Just ensure that you are being honest with yourself in assessing if you 100percent apply yourself to the job or not.