Is it normal for people to try to kill themselves.

Yea. Um basically I hear someone at least threaten it once per day.
I grew up with my mom having psychotic depression, and she always try it in front of us.
My sister has too much anger and freaks out and pulls knives on herself other people.
Ive been in institutions since I was 13 (im 16 now). And people would often stab themselves with the forks or light themselves on fire.
My friend from institutions recently killed herself. My other friend overdosed on the same day (she survived!).
And I keep hearing people talk about it and i see people hurt themselves all the time.

Idk why this is so common. I do everything I can to help, but this stuff happens everyday. I always hear people say suicide is a big deal, and I agree with them. But everyone acts like its just so normal. Its freaking me out. Like idk how its possible for just about EVERYONE I know to get this upset. It seems impossible. Im really confused. I feel really bad.