sometimes, for no reason, i start to feel very anxious almost like i am about to give a speech in front of thousands of people, only ten times worse. it has actually gotten to the point where i'm so anxious it hurts. then my vision becomes blurry everywhere except for the area in my direct focus. then i recall images from my mind, but i can't remember if they were a dream or real, which causes me to become more anxious. i have tried drinking more water, eating a healthier diet , and getting more sleep to see if any of these would cause it to stop, but none has. why does this happen?