You are already enough. Although, there may be skills you wish to learn, circumstances you wish to change and goals you wish to reach; who you are is already enough. When you say "I am enough" to yourself you will notice thoughts and feelings that arise from inside yourself. If you notice an inner thought or feeling that disagrees, or casts doubt - just say "thank you" to those thoughts and feelings; and repeat "I am enough". Continue to remind yourself of this fact, you will feel better and better about yourself as you will also notice, your increasing happiness and confidence.
Creative Credit to @MugshotMedia and @MaxxKochar