^ He's had a panic attack and shot drugs that cause respiratory depression, when you have a panic attack, it's easy to develop around a false theory you create. Meth users develop theories of having a heart attack, and every symptom they have is in line with that belief, except they don't have a heart attack and their mind is playing tricks on them.
In order to feel pleasure from dopamine enhancing drugs, the brain needs to lower the activity of certain areas that distract from the pleasure, like memory or the cortex. An area that is also temporarily lost is a cortex portion responsible of behavioral habits and body language. A person high on drugs might find himself never touching his hair when usually the person is always arranging his hair with his right hand, not smiling when usually the person smiles, it can also be things like closing the toilet lead when the person normally always leaves it open. You are in a position where you have to think "how did I used to do this? Jees I'm gona appear weird" for things that you normally do without thinking.
Sometimes the cortex activity is so low that you stop seeing the relation between the naked women in the porn, and you squeezing your dick. In these times, I can just close the porn, and actually, closing my eyes enhances the sensations and I really see no relation between what I feel and women. I feel it like a soft 3 dimensional space that bends inwards as I squeeze, and I just stick with that space and it's nothing more than that. That's because at that time I am in nucleus accumbens, the connection is direct, and whatever routes that got me there are irrelevant and they all vanish, the cortex really stays out of this, and so everything becomes extremely irrational.
I can tell between those states even when I am deep inside them I know where I am and what I need to do. I also know I cannot show up for work or else I am going to scare the living shit out of everyone. And this is nothing to be ashamed of, if you don't understand what's happening you might be ashamed, otherwise, you know you deactivated those regions, you don't have your whole brain with you, you understand that, things are good. This is something not many people can do, if you don't know where you're at, what to expect from your state and how to identify symptoms of that state as being normal, you can easily panic and things can go south because you no longer know where you're at.
This comes with practice, I have lost count but I personally have been in such a state between 3,000 and 5,000 times, each time for an average duration of 16 hours. So it does take a lot of practice.
The worst with these novice drug user panic attacks is that you find yourself stuck looking for clues to validate your theory, of heart attack, embolism, you name it...instead of enjoying the high. And this is how you can break out of that panic, by comparing what you planned to do before taking the drug with what you are doing now. You didn't take the drug to become detective Colombo...so why are you acting like him? Probably because your brain is failing you, but you have the power not to fail yourself even in that state. Even if the panic occurs, just sit there and notice it, as if it was another sensation, don't engage in it, don't interact with it, just observe, 5 seconds later it's gone.
It can't stay unless you feed it something. You should be feeding your pleasure not your fear, so be conscious of that, if you only observe it, as a phenomenon, it will pass before you even know it. Don't relate to it. You have nothing in common with it. It's just you, the pleasure and nothing else. So the smart ass in you that's making theories, give him a rest, he is like an actor on your stage, toss a tomato and make him leave. He is just a monkey. He's not you. The real you, is that which observes that process take place. He might have many tricks say "hey look you don't breath properly, it's the shot! It damaged your lungs, see I make sense!" Treat that voice as another phenomenon.