HeadphonesandLSD: You said that you "have come close to oxycodone OD a handful of time", can you elaborate? Were you just on oxy? How do you know how close you were?
Sometimes it was just oxycodone yes, but typically in the form of roxicodone meaning instant release pill with nothing but Oxycodone in it. I might not have been too clear as I said every time it happened with just Oxy for me involved mixing it with other things. I never had my own prescriptions, and I would go out on the weekends mostly to house parties. There wasn't much to do were I grew up but hang out at a friends place or hope someone was throwing some kind of bonfire/house party. We did a lot of driving too of course, since after 2am you pretty much have the roads to yourself
Anyway, most nights you were not sure what you were going to run in to. Usually you'd bounce from house to house looking for anything to catch a buzz on. So you'd run into pain killers one place, xanax another, and might run into stuff just by chance. I'm sure I don't have to really explain that to you, but that's the environment I was in.
Also, as far as opiates go we got to sample just about everything but H. I got my first real nod off old school Oxycontin before it was even well known. If you think about it maybe you'll figure out where I reside.

Point is, if it killed pain we tried it.
The substances that scared me the most, in order, would probably go something like: Opana ER, old school fentanyl gel patches, Dilaudid (first time, did way too much and mixed with xanax and lots of beer), old school Oxycontin (one bad experience, never did it much), and lastly Oxycodone mixed with xanax.
Anyway I can tell I'm close to doing too much these days. When I suddenly feel cold, and I'm covered in sweat, and I feel like I'm gong to pass out unless I lay down. That's how I know I'm in the danger zone. Sometimes I get a weak stomach too and feel like I might vomit, but I have a strong stomach so this isn't a good indicator for me. A naive user would most likely panic in that situation and would probably call for help (well, one would hope depends on ROA and what they're doing). A "junkie" might not for fear of police getting involved, depends on who you are. I mostly got in trouble because I'd try to "ride it out" instead of calling for help.
For me I was always trying to be careful, but once I got off and started chasing that high I did stupid shit. I was also one of those people that wouldn't go to bed sometimes and instead would stay up chasing until my supply ran out. Dark times near the end of that run.
That was certainly an interesting story... that would scare the fuck out of me if I woke up after nodding off with my lungs hurting that bad. It's weird that they hurt when they become seriously depressed. Of course you couldn't have been "not breathing" for the whole time you were out. I wonder how that works. Do you switch from shallow breathing to no breathing at all? Obviously you can't say for sure because you were asleep lol but I am still curious non the less!
I was totally out of it and I only know the times because I was watching TV when I'd nod out and would check the times as soon as I came to. I didn't stop breathing all together of course, but based on how shitty I felt I'd say I was breathing just enough to not die. It scared me good...for a couple of weeks.
At any rate in all my time, and with all those bad experiences that was the worst of all. I should also note that at that particular time I needed about 50mg of Oxycodone to feel good, and while I knew Opana was potent and not to he fooled around with I simply lost track of how much I'd done. If I would have been crushing and cutting out those I wouldn't have did near as much. I should have been paying better attention, but I was too focused on what I was doing at the time.
Oh, and I should mention ODing isn't your only problems. One of these days I'll tell you about the night I put a car in a ditch. I'll cut it short and tell you the moral: Never mix cars, oxycodone, and a cell phone at 3am on a deserted highway. :D