I have heard about this, it is more a common problem among men than one would guess. It's a manifestation of social anxiety. It goes hand-in-hand with other forms of social anxiety and is treated by the same methods as those other forms. A psychologist or therapist would really help, if the problem is one that bothers you to a great extent, or there could be an online support-group. A regular doctor could refer you to a psychologist, or a little online research on "social anxiety [disorder]" would give you more information. I wish I could be of even more help than this.