How can a man with small feet get rid of this complex?

What complex?: If you are just concerned about shoe size, people come in all different sizes & there is nothing you can do to change the size of your feet. If you mean that you are concerned that small feet are related to other body parts being small, there is no correlation, so don't worry. If you mean that you feel like you have a "complex" worrying about your feet, talking to your dr or a therapist can help.