Real anxiety with potent physical symptoms is very much not "all in our heads"
Anxiety can be debilitating when it strikes. On top, it can create these crushing feedback loops.
I mentioned above the common-ish version in severe agoraphobia -- where fear of having an anxiety attack becomes powerful enough to cause them all by itself. That is the usual root cause of those stories you occasionally hear about people who lock themselves away for 10+ years, never going outside or being with anyone, except maybe one or two "safe people"
It sounds like you ended up like me with a version where the feedback loop is anxiety -> palpitations -> health-anxiety -> major panic -> health panic.
I have read hundreds of detailed descriptions of the symptoms of all manner of serious diseases over they years, looking for the clue that I might not be dying. Not because I "really thought" that I was, but because I was having self-perpetuating anxiety over it.
It's not the same as hypochondria, because I don't really rationally think that I have the condition in question, I just persistently fear that I do.
It's nice to talk to someone who understands. I'm glad you are coping OK for the moment. I am too.
We will make it, somehow.
Funny thing was, for the longest time I always thought "I'm pretty damn healthy, except for the allergies and asthma." Never really worried about my health much, except a little when I got a bad case of bronchitis.
Those thoughts and feelings suddenly stopped right around when I turned 30 and started getting combinations of minor symptoms just about everywhere on my body off and one all the time.
Probably also that's when I started knowing people that died really young and suddenly (or had close calls) from various things like sleep apnea, heart attacks, leg clots, aneurisms, etc. Seriously, video/board game industry has had quite a few of these young but sudden deaths lately, including some people I knew personally.
When you have symptoms that match those things, it's hard not to feel like it's better to be safe than sorry.
There are surgeries that can help with hernias (which can come and go like that).
Another thing, have you tried Nexium? For me that has been really useful to reduce symptoms (although I do still have some serious symptoms). But it sounds like you have a more significant hernia.
If I do have it, I think it's still pretty minor, at least compared to some pictures of hiatal and epigastric hernias I see online. It hasn't ever stuck out that far, and no doctor has ever noticed a problem.
Yet another reason to lose a bunch of weight. Throw it on the pile. Need to get my act together.
Also, I used to take Prilosec, but usually now I'll just give up all caffeine, soda, fatty foods, most tomatoes and citrus for two weeks, and that seems to put me back in a state where I can tolerate it again. Until I push the boundary again. I've heard some worrying things about long-term use of some heartburn medicine, so I try not to take it.
I'd go to urgent care and they'd always be like "well you have a normal EKG but you should go to the hospital to be sure" and then the emergency room will talk to me, take my blood, monitor me for a few hours and take my blood again (sometimes it takes awhile for the markers of a heart attack to show up), and then tell me it was probably just heartburn.
I've gone five times in the last 2 years for this same song and dance (I skip urgent care now). I have had these feelings happen about 20 times besides that, so I'm not even going every single time, there's just some especially scary ones that make me go "It's probably nothing, but just in case!" Last time I was driving and could barely focus on the road, which was new. I was pretty close to an ER and even then I pulled off the side of the road and tried to calm down for 20 minutes before finally deciding to go in.
I'm only in my 30s, but I have seeing more and more stories of people dying from heart attacks that young (I know it's still rare, but it can happen), so that doesn't help. And if for some reason it ever does become a heart attack, I probably won't tell the difference and might not go in for it, and end up dead.
So yeah, anxiety over heart attacks can be no joke. I have real symptoms that manifest over it. Sorry you're going through this. I don't know if it'll ever go away for me, myself. Worried it might just be something I have to live with from now on.
But I'm fine normally except for the rare attacks. Even this pandemic isn't really bothering me too much, although I'm doing my best to avoid getting it, especially since I have other issues that could lead to a bad outcome (like the already mentioned asthma).