If you believe that you're a person who can talk to any person of any age, skin color, physical quality (hot woman, old man, ugly child, etc.) without the fear that you're not worthy enough, I think height will not matter.
Confidence comes from being comfortable with the body you have and projecting that body language to others that you can be liked. Girls want that regardless of how tall you are, how fat you are, how ugly you are, how big your penis is, etc.
Also if you're short and a girl doesn't want you because of your height, then perhaps you're better off anyway. Superficial qualities really do not matter in the long run.