“I have no idea what's going on”

I've been having these weird heart flutters that last mere seconds at random times. Sometimes once a day, sometimes 7 times. There is no pattern to them and I have them in any point in time regardless of stress level, relaxing, walking, etc. I will have random moments of chest pressure on my sternum, my head will feel like a balloon at times, and will have random aches in my body. My blood pressure is fine, I recieved a heart untra sound, chest x-rays, an in house sleep study, had a 48hr ekg Holter (which I was unable to pick up a heart flutter because I can go days or even months between them,) blood work done, and none of them had anything to report. I do have anxiety however, I do feel like there is indeed something going on. I am a 29 year old male at 172lbs, 69in tall, serving in the army and eat a decent diet. I'm wondering if I should pursue getting my brain checked for imbalances or my arteries checked for blockage. These palpitations or flutters also leave my chest in pain, dizziness, and short of breath but I've been to the ER on multiple accounts with nothing bad reported in their tests. Thank you