What Causes Hot Flashes And Breathing Difficulty?

Yesterday i was sitting on the couch like any other day when i started to get really hot. So i stood up and walked outside to catch some air, well on my way out i keep getting hotter and hotter and my vision starts to go spotted and eventually black.This wasnt just like i stood up fast and got light headed cuz that happens all the time. But as im outside my body starts to go weak and its hard to stand, with my vision already gone and my breathing getting harder an harder i lower myself to the ground. At this point i was confused and trying to knock on the back door for my girlfriend to come out i didnt have enough strength to even knock or yell her name. The next part is real fuzzy but my girlfriend helped me up and walk to the car to take me to hospital which she says i was stumbling and hard to support while getting to car. But once we were pulling out of the driveway i came out of whatever happend and told her i did not need to go to the hospital. I was drenched with sweat and pale-white. Please give me any information you can and what further actions i should take. Im 21 yrs old, 6 8 190lbs and in good health so i thought. 2 older brothers have terrets and mother has MS. Looking forward to hearing back asap. Thanks!