Hi
what you describing is normal and harmless. I been having feelings like this since i was 15/16 and im 23 now.
I have had times where i feel relaxed and watching a dvd or snuggled with my partner etc when all of a sudden il just come over realllly scared, il litreally jump up and feel like i cant breathe and il start pacing the floor and just wondering to the phone going to phone for help, by this time my hearts beating so fast and i start getting really hot and dizzy and literally feel like im dying, il struggle to catch my breath and can barely talk, and then get flashing images of me lying on the floor suffocating type thing!
Then maybe 20 mins or so later il suddenly begin to calm down and actually be able to sit still and take deep breathes!
When im eventually as calm as il get i will think to my self "where did that come from?" how could that happen when i was enjoying my film.
Believe me all kinds of things go through my head, its very hard to believe that anxiety can make you feel like this and just comes out of the blue like that, een when we not in any akward and unrelaxed situations!
I used to get this at least a few times a day, but now i maybe have 2 or 3 reallly bad attacks aday, but finding ways of managing it and challenging it is the best way!
As for the fear of dying.. that is perfectly normal, everyone on this site has that fear - thats why we are here!
As for the citraplam your taking and that, i got advised to use that and was told it could take up to 6 weeks to work, i guess it may depend on the dose, i chose not to take it when i was pregnant at the time. Give it time to kick in, if you feel no different then talk to your gp.
If you ever wanna talk, feel free to message me