Hello I am a 27 year old man, I weigh 197lbs and am 5 11.For the last four days I just have not been feeling like myself. I get very spaced out and almost disconnected. It tends to worsen with exercise or running, it gets to a point where I think I might faint, like I almost do not know where I am. I think have acid reflux or possibly a hiatial hernia. I also recall being bit by a rather large strange looking mosquito about 5 days ago. I live in Brooklyn, NY. Could this be a heart/circulation problem? Thanks
It certainly sounds like it, but there is no way to tell without more history and some testing.  You should go get checked out.  Your problems fall under the category of loss of consciousness with loss of postural tone.  The list of categories that can cause included both heart rate, blood pressure, disorders of brain function, and lack of oxygen