I can only relate my experience which was similar to yours. One big difference though- My EP immediately recommended an ICD defibrillator to prevent a run of ventricular tachycardia which could be fatal. Although I’ve never fainted, I would occasionally feel dizzy/light-headed for 1-2 seconds. This happens because there is not enough oxygen carrying blood getting to the brain to sustain consciousness when your heart races. If the arrhythmia goes on for too long, dizziness rapidly progresses to fainting, and eventually, possible death if the rapid heartbeat is sustained.
Because I had an implanted heart monitor, the EP knew exactly what my heart was doing and took action. An ICD defibrillator has a track record of being 99.9% effective in preventing sudden death from an unpredictable arrhythmia by shocking the heart back into preset, desirable beats per minute.
I believe you would be well served by finding an EP who doesn’t dismiss your symptoms. From your post, it sounds like you need a thorough workup including long term monitoring for an accurate diagnosis. An EKG is nothing more than a snapshot in time and is likely to miss intermittent arrhythmias.
Don’t hesitate to change doctors if you can’t get the attention you deserve. See an EP, at the best hospital you can find, even if you have to travel. Do not see a general cardiologist for your issue, but rather the EP specialist.
Best of luck to you!