Brown/Reddish/Small blood in Saliva

I've been stressed out every time I feel something in my body I always assume to have a very bad disease such as cancer lung disease. I cough every time I am not comfortable, smelled smoke, or unpleasant smell. I experienced globus in my throat, I frequent swallow, got burning sensation at the back of my nose, then yesterday I forced to spit my phlegm using my nose and blood came out together with phlegm but in small patch. Then this morning I have brown/reddish saliva but after spitting, the brown colored saliva was gone. Please answer me. Am I stressed? Is it GERD?

any scope done?

Are you get any further forward with your issue.