Unexpected Whity

So i've been smoking for 5 years and for 3 years regular use (2-8 spliffs a day).
i went on holiday for 5 days with my family, i was dry so i just quit for then. Got back last night and whent to my mates house. we rolled 4 joints while watching a film. After the film i rolled another while my mate made some food. All this time i was fine and stoned like any other time. we then went to chat in the kitchen. i was standig up listening to convo then suddenly everything whent fuzzy psychedelic white, sort of like an extreme head rush, it felt like the beginings of a whity but i did not feel like i was about to vomit. i collapsed banged my head (not hard) on the fride fell on the unlit stove and collpsed on the floor, however at the time everything was white, but it quickley subsided and i found myself on the floor. i quickely brought my self up and felt like myself again, completely fine, and i whent and sat down. i was tripping a little (fuzzy a colourful patterns. I havn't whityd for 4 years. I do not know why this happened, has somthing similar happend to anyone else?

yeah, my freind i was smokign with for his first time. 2 bong bowls and he collapsed for about 45 minutes on one of the mainstreets on the wayt to my house, i didnt ditch him though, i stuck with him, and got him back to my house. he layed down, and kept trying to hide from the sun in my shadow, stuttering when he was talking, really weired, and i dont think he was faking, hes a pretty nice, honest guy.

One time, I was on my way to the hospital to get an operation done. Nothing serious at all, but I was way nervous and hadn't smoked in like a week. I was riding with my old man, and he pulled out a spliff in hopes it would calm my nerves before we got there. Well we smoked this dube, and we stopped at the gas station. I didn't feel quite right, so I went in while he was pumping gas to use the restroom. I walked through the store to the bathroom, and when I got there I decided I was gonna pass out or something. I walked to the cooler instead, and grabbed a sprite. I walked up to the counter and sat my soda down, waiting for James to get done pumping the gas. I knew I was going down, because I'm practically holding myself up with the counter. I tell the clerk I'm leaving my soda there, and going to my car, that my husband will pay for it when he comes in. I turn around and take about 3 steps to the door, and I went down! And down hard! I took out a whole mother fucking beef jerky rack. The next thing I know, I'm laying on the floor with the clerk smacking the shit out of my face. Needless to say, she wouldn't let me leave until after an ambulance came. After I came to though, I felt just fine. This has also happened to me a couple other times, but not in public.
I think maybe it's lack of oxygen?
Just be thankful it didn't happen to you in the middle of a gas station.