I don't believe height should hold you back. But your images can. I think if you focus on your images, focus on getting quality and working with creative ambitious people, and think of modeling as a business and then starting your modeling career will be easy.
Here are some tips on clues to know a photographer is professional:
1. Does he have a problem giving you References? If so this is a sign he is a bad sport.
2. He doesn't want to have a meeting ahead of time, and refuses to show you his portfolio book and just wants to plan the shoot, no questions. Just remember an online portfolio isn't good enough, a professional photographer will also have a portfolio, which you can hold in your hand. Or at least a tear sheet from a magazine his image was recently inside of.
3. He knows nothing about lighting and makeup and styling and just wants you to hurry so he can take the photo. Bad sign.
4. He had no goals, ambition or creative ideas towards photography. He doesn't ask yours either. This is a sign to leave and not waste your time.
5. He doesn't provide what you agreed upon. This can define the importance of saving emails, and agreements, especially if money is involved.