Lightheaded

I constantly feel like I'm passing out....I be sitting down n it feels like I'm slowly passing out....I'm frustrated....I went to the doctor yesterday they found nothing wrong.... could this be anxiety...or am I slowly dying.....I'm so worried...

I feel very slight pain in my face especially my forehead n left side of head,n I'm always stuffy....I can't shake thinking that something is wrong inside my head....

It's me anxiety x try not to focus to much on the feeling cos ya just feeding anxiety x