Neurological Disorders :: Dizzy/lightheaded Racing Heart

I have been experiencing dizziness and lightheaded feelings every day and night for the past couple of weeks. I already had issues before (for almost four years) but never as bad as recently. On top of that, my face gets flushed easily but I also get cold spontaneously (almost as if I have a fever but whenever I'm at the doc my temperature is ok). My blood pressure used to always be within the 115/65 range but recently it's been around 135/80 resting and can go up to 150/85 just from talking a walk. After walks I usually feel more dizzy, my heart races with any light physical activity (I used to be pretty physically active when I was healthier). To add to the symptoms, I also get visual disturbances at times, as if my eyes can't focus, and I get dizzy when looking down or following faster moving objects (example- I tried to play video games and couldn't continue after 10min). My sleep has been interrupted, every night I wake up dizzy and feeling uneasy, my heart rate always jumps from slight movement. All of these symptoms are building up stress and anxiety, I feel lost and hopeless because I am constantly miserable. My blood work always comes out fine, doctors can't find anything "obvious".

Just wondering if anyone has similar symptoms or would have any suggestions... To add to this, I am 24 years old, non-smoker, don't drink and my BMI is within range.  Doctors have not been able to help me and most of them don't understand that this is completely preventing me from living a normal life. I get light headed and dizzy if I try to exercise, walk up the stairs, go in an elevator, turn too fast or sometimes it happens from just sitting and not moving. Usually my heart rate is part of the symptoms and it becomes elevated spontaneously.