Hello Adellic, sorry to hear your having a rough go of it.
I to have had plenty of fear about my heart and or a seizure. I might be wrong here , but if your like me, I'm guessing you may be spending a good amount of time looking up your symptoms and becoming frightened by all the negative possibilities. I actually had more testing done on my heart yesterday, yet again, and I'm still heart healthy despite having just about every heart attack symptom to some degree or another.
I go in for a stress test later today, nine hours to go, and I'm pretty sure the results will be fine, just anxiety.
I know it's really hard to trust that what's going on isn't something bigger, anxiety has a wide array of symptoms and none of them are much fun, down right frightening actually.
Well I would like to say I don't rush to google every time my body does something new and disturbing It wouldn't be honest, though I'm on there much less often. If this is something you're doing I think it's good to remember no internet page can provide an actual diagnosis , they can tell you weather or not it's usually an emergency , and many of the symptoms to at least some degree seem to be similar to an end game problem.
The only way to know for certain is to go in and have your concerns addressed by a doctor.
That stated I'm fairly confident what you are experiencing is just anxiety.
I try and keep busy, and if an attack happens just kind of go with it, trying to fight it seems to make it so much worse. There are also things like the box breathing method and meditation, and good old technology as a distraction, that seem to help calm things down.
Maybe try and figure out what really works for you. I whistle songs, seems to help keep the breathing normalish and it's soothing to me. Though I bet my neighbors hate me when I wake up in a panic late at night
If you have real concern about health things you should have the looked into, always better to know.
Sorry to have been long winded, hope you find something that works for you and until then just hang in there. It gets better.