Hi jrt,
First of all, I echo the advice given by all above to see a GP. They’re generally useless, but they take anything like that seriously and are the gateway to more specialist help.
Secondly, from reading everything you’ve written, it definitely sounds like panic attacks. I suffered them terribly in the Summer of 2014. Apart from the lack of pain (although you may still experience chest pain during a panic attack), the symptoms are nearly indistinguishable from that of a heart attack; the difficulty breathing, the racing heart, the tight chest, the cold sweat, and the feeling of impending doom. It’s a very, very frightening experience.
Sometimes, an emotionally stressful event can precede them, sometimes by weeks, months or longer. Although, in my case, there was NO trigger. It appears it’s possible, for no specific reason, for the levels of various electrolytes in the brain to fall slightly out of tune for a period of time, and it is this alone which causes the attacks. It’s important to understand that panic attacks are the result of a chemical imbalance in the brain, which sends your fight or flight response into overdrive, hence the very physical symptoms.
I was prescribed Sertraline (an SSRI, or anti-depressant), and took it religiously (still do) every day. It took a good six months for it to take effect, and after 12 months the attacks had stopped altogether. If you’re prescribed something similar (an SSRI), the doc will tell you it will take 2-3 weeks to a couple of months to take effect; this isn’t true in my (and lots of other peoples) experience, and it can take as long as a year of continuous use as it did with me.
My advice would be get yourself to a GP, where you’ll probably be prescribed an SSRI, more than likely Citalopram. If so, keep taking it, even if you think it’s not working. You can try other ways to treat this, but at the very least, if you keep up with anything you’re prescribed, you should get some relief in a finite (i.e. 6 months to a year) period of time. Start the treatment early!
Best of luck with it mate, and keep us posted.