check panic attacks if you're having a problem with anxiety - if you have one, it can do all kinds of things. some people think they're having a heart attack or even dying.

and you were probably seriously dehydrated which doesn't help anything.

my bet is it was a combination of things and the doctors will never find a thing.

if you think panic attacks, try some meditation or other natural methods - my son has terrible anxiety & the prescription method only leads to more problems
and, when you decide to smoke again, pick your weed carefully. some helps anxiety, some makes it much worse.