So the stories about people ruining their hair to the point of falling out?

So I hear all these stories of people ruining their hair to the point of it falling out. Never seen it, but I wonder how bad it has to be?Here is my story...bleached blonde (various shades from platinum to carmel) over the years. Natural color is a lighter brown.� I had the brilliant idea to go darker.� Well it was dyed almost black.� I hated it.� Had it done again to lighten it up.� Not light enough.� Had it lightened again.� Still not light enough.� Now I am thinking I just want to go back to blonde. Will this break all my hair off?� This has been over the last month, three dye jobs.� Will going in another time and having it lightened really ruin it.� I really do not notice much difference in my hair texture right now, I feel safe about it, but I am curious.� I want it lighter and she wil most likely use color vs. bleach to lighten it.� What says the hairdressers out there say.