Last night, I was laying in bed, and I felt very very relaxed, and I noticed my breathing was really slow. I was breathing out, and It was like I had no need to inhaile, I didnt feel like I was sufficate. I got scared, and got up, I did a lot of reality checks. I had to breath in. Im glad Im not dead. This wasnt like a old hag expirance, and it wasnt lkie SP, because I could move, but when I laid down I got that very deep relaxed feeling, but was steel breathin allmost to the point of stoping. It was a expirance I dont ever want to repeat.
My time perceptio was moving slow allso. I hadnt smoked anything, and I wasnt drunk.
Lol! There was no need to precise this last point, we believe you. 
I don’t think it’s due to time perception. Some meditating techniques can get you in this apnea state. I think it’s because you were very well relaxed. I’ve had this feeling too when just waking up that I didn’t need to breathe. Of course, it doesn’t last very very long. 
this doesnt have to be all that bad, if my knowledge on the biological functions of the body are somewhat accurate. which i hold no guarantees for 
from what i know, your SC will regulate your breathing for you, and quite well. otherwise, we would constantly have to think about breathing, which isnt all that practical. i am pretty sure you’ve noticed this, too. now, some times, your body needs hardly any oxygen, because it isnt using that much of it. if memory serves me, over half of your body’s oxygen supply is used by your brain. this means, that when you are feeling relaxed and dazed, with no real thought going on, you use less oxygen. this means that you dont have to breathe all that much while relaxing. you probably know that you breathe alot more when you are working out than when you are watching TV.
long story short, you get relaxed, you breathe very slowly. this can, in some cases, get ridiculously slow, but that isnt something to worry about, because your brain will kickstart your breathing by itself if you ever pass out, as a sort of built-in safety feature. so if you notice that you are breathing really slow, just go back to relaxing. the worst that can happen is that you pass out from lack of oxygen, in which case your brain will force you to breathe again, and after a few minutes, you wake up again, with no harm done. i think…
So I was basicaly doing WILD, I loved it. The feeling of being that relaxed was so cool.
I’ve actually had a similar experience whilst attempting WILD. I was becoming really relaxed…when all of a sudden I realised my breathing was really slow and deep. I was like…what the…and started freaking out, which obviously ruined the whole thing 
The experience was uncomfortable but nice at the same time…Odd. 
I have noticed my breath being really shallow when I try to WILD sometimes. I start thinking I probably should breathe more, then remember it’s automated but still feel too uncomforable with it not to do anything about it. It’s in a very relaxed state too.
I’ve heard stories of yogis that put themselves in a state of so low metabolism that they don’t need to breathe or the heart to beat. I don’t know maybe it beats a little. anyway, then they bury then fora few days and they come back up alive. It was in a schoolbook of mine from 7th grade.
Maybe since you didn’t feel the need to breathe you got into such a low metabolic state as that.
if you are breathing very deeply and very relaxed you can go an extreme amount of time without having to inhale and without NEEDING to inhale.
i’ve gone for what felt like a minute or longer actually. its not like holding your breath.
so if you’re in some sort of medtiative or altered state a sense of timelessness can have you feeling that its been far too long since you last breathed, but just go with it, you’ll be okay unless you feel like you’re choking and NEED air… such as in the case of perhaps waking up in SP and having apnea at the same time, from lying on your pillow wrong.
i have tried this once:
I got myself realy relaxed, and breathed slower and slower, until i was really relaxed. Then with the aid of a stopwatch, i breathed only once every 60 seconds, yes 1 breath/minute.
Last year I got in this state a lot in Science class. That’s the class I’d always fall asleep in. It’s also led to other stages in WILD. Nothing to worry about at all. 
Did you ever had a LD in class ?