Near fainting and extreme exhaustion.

I am 25 and for the past 1 year I have been struggling with this problem and I have tried multiple hospitals and doctors both inside and outside of USA. 1. Vision changes. Even with glasses I start seeing blurry. The vision blurriness is accompanied by unusual and sudden body heating and sweating. 2. A strange hollow panic kind a grip like feeling in the tummy (kind of burning and palpitation), and a strong rush from the tummy to the head. (that’s the only way I can explain the feeling). 3. A strong feeling of pull on the back of the head like as if you are now going to fall, I mean its similar to you are about to faint but you really do not lose consciousness. I guess I can say near fainting. 4. Ringing ears and difficulty normal breathing. I have to apply so much effort to breathe. 5. Heavy head and buzzing on the back of the head and ears. 6. Occasional shaking and feeling woozy. 7. Even minor exertion of the body like walking for few minutes, cleaning the house, or exercising make