Why do I faint or feel faint in crowds

During our Army roll call and accountability formations I have felt very anxious, I can feel my heart is not pumping right, I feel weak, sweaty, see black spots or closing in darkness, usually takes a few minutes before I get my self togeather, but I will be disinorianted after. I feel my anxiety plays a big role, but dont know what to do about it.

you might have agoraphobia, that is, an anxiety disorder that may stem from a fear of crowds. the best advice I can give you seeing as I dont know you is, you might what to think about seeing a psychologist as to what your problem might be.