hard to breathe

I have gotten this I guess I am not raelly sure what to call it, but I have hard time breathing almost everyday, sometimes it feels like I am going to pass out. It happens at different places, like if I eat to salty food or when there are to many people around, but then not when I teach business classes. I am not sure what it is, but it scares me, I feel like my throat is dry and I always have to have water with me. this does not help at all in Iraq and that is where I am at currently. Is it just some mental thing going on and how do I control it. before it was very bad and I would get really scared but now I am learning to control it but it is taking to much of my strength. what do i do???