Turning blue and falling over onto the floor is not fun! A lot of beginning flutists become very frustrated because they become dizzy while they are trying to practice. They can't conceive how anyone could hold a whole note THAT long. The reason they feel this way is that they are basically hyperventilating themselves! Some students may hear their teachers say "Breathe from the diaphragm" and not understand what they are talking about. While breathing really doesn't involve the diagragm directly, what they mean is to breathe from your tummy. Breathing with the flute involves the same muscles you use when you cough or laugh. Try some of these excercises. I hope they help! Stick with it!
1. Place your hand over your stomach and practice saying "ha ha ha" right from your tummy. Can you feel your stomach rise?
2. Lie down on your bed or the floor and place your flute book on your stomach. See if you can make it rise and fall by breathing with your tummy.
Once you're got these mastered, see how it feels to play some scales with nice big slurs. Good luck!