I saw your post about high notes on the flute and that no one really helped you with that. I'm a fellow flute player and have been playing for quite awhile now.
All notes above the staff are unstable, so that's why they sound so screwy. The main way to lessen that ear bleed that it gives everyone is by 1. Making sure your C Major and B-flat Major scales are in tune. Do this by your mouth. (And use the normal way first. ) 2) Make sure you have the right fingerings and pressure from your mouth.
This is what helps me with my flute and piccolo. If you ever need any help, feel free to hit me up!