Don't know how much help this is, but....
When I was about 5-10 years old, I used to get nosebleeds about every 3-4 months. Usually it was from playing/roughhousing around and bumping my
schnoz or other things boys do at that age. When I was 8,
this happened, which was as bad an injury I've ever had. At least once a year, I'd lose enough blood to get light-headed, but not enough to ever pass out. Once I learned you couldn't lose enough blood without losing a limb, I rested a lot easier about blood.
Getting used to the sight of my own blood (although I briefly look away from needles the instant they're poking a vein) is now like looking at oil draining out of an oil pan...if it's to intended to occur, that's okay, it's normal; if not, then maybe it's time to calmly do something about it!