It’s even started to affect what I eat as I won’t eat anything I feel is unhealthy as I’m worried my arteries will clog up and cause a heart attack which is my biggest fear - I think this is because when I had my panic attack that started this off it felt so much like what I imagine a heart attack to feel like.
When the first panic attack happens, many people feel so awful that they do end up in A&E, believing that they are about to die, but it's really important to know that no-one ever dies from a panic attack.
Our bodies do weird and wonderful things all the time. We make strange noises, get odd pains for no reason and bits of us randomly misfire occasionally. Most of the time we dismiss, or totally overlook, these anomalies.
However sometimes something alarming happens at a time when we are already feeling fragile. It could be that we're suffering from a hangover, in an unfamiliar place, recovering from illness, overtired, hungry or thirsty, stressed or feeling emotional and that unexpected extra heartbeat or stabbing pain frightens the life out of us. This fear ignites the fight or flight response which does all the things it's supposed to do but simply has the effect of confirming our worst fears.
Even when we recover, which either happens in hospital (a scary experience in itself) or naturally (which normally happens within 30 minutes) our minds and bodies are now on full alert in anticipation that the next attack, which might kill us and that very fear is what sets off the next attack.
So, how to deal with it? First of all, stop the fear. Accept the truth that no one ever dies from a panic attack. Doesn't happen. So if it can't kill, or even hurt you, it's far less scary.
Secondly, when you feel it creeping up try to sit down somewhere quiet and box breath through it (lots of videos on YT on box breathing).
Thirdly, concentrate on what you're going to do when in subsides. What's for dinner? What are you going to watch on TV later? Or just random musings; what are your thoughts on your neighbours new curtains? Will prince Andrew go to jail? By taking the emphasis beyond from the panic attack you are mentally accepting that it's not important, it's just a nuisance that will stop in a few minutes. Once this happens they attacks will lessen in frequency and intensity and finally disappear.
HTH.