Terrified and not knowing what to think

Have you worn a 14 day zio patch monitor? I have PVC'S and tachycardia I'm on metropol and flecinade. I'd be scared to fly to. God bless you

So sorry you are dealing with all of this. I've experienced heart arrhythmia for years and finally got diagnosed with Afib. Its got to be difficult to feel so bad and not have an explanation. They found mine on day 28 of a 30 day heart monitor. EKGs only show the moment that they record. A 30 day heart monitor might reveal more??? Just a suggestion. Good luck!

I think you should get second opinion. Tachycardia should be treated as it weakens the heart. Also can lead to stroke.

I'm 81 and have had similar feelings but luckily only intermittently, for the past 20 years at least. About twice a year in the ER getting checked out, sent home.
Two and a half years ago diagnosed with ovarian cancer; surgery and chemo. After that my resting heart rate went from the previous 78 into the high 80s and 90s. (I'm in remission)
The anxiety thing is a real bummer because at least for me it feeds back and makes the heart stuff worse. I have found that a small dose of Xanax doesn't necessarily calm the heart down right away, but leaves me less anxious and more able to function. And sometimes it's enough to break the cycle and the palpitations subside.
After much effort I finally became the patient of a cardiologist, and documented the severity of the palpitations. I am taking metoprolol and just as of 2 weeks ago flecainide. My resting heart rate has dropped a little bit, but I had a good strong flurry of palpitations yesterday again.
You might consider getting a Kardia, which works with your smartphone to do a 30 second EKG. As often as you like.
You get one line with just two thumbs, and you get six lines with the two thumbs and a bare knee. (Corresponding to the arms and ankles of the usual EKG) You can download it as a PDF and send it to your doctor. You can just buy the little machine and download copies for your own doctor, or you can pay about $100 a year and have their doctors look at anything they flag as suspicious. I like being able to document the things when I'm feeling them, or alternatively to see the little zig zags going rhythmically along when I'm feeling anxious and weird.
I find it really hard to sort out the anxiety symptoms from the actual heart symptoms. I also take an antidepressant, remeron, which helps with the anxiety. I used to take it all at once, at bedtime, but when I realized that taking it caused my anxiety/heart symptoms to subside, I split the dose to make it more even through the 24 hours. I think it's helped.
Not a solution, But you might look at trying to treat the anxiety per se... See if that makes life more bearable.
Facing death at 81 seems very appropriate, and very inappropriate at 33. But that's partly because modern medicine has done such a good job in general; your great-great-grandparents would be sad but not surprised at an early death. I'm sorry that this knowledge is being forced upon you at such a young age.