friends suicide

I guess I just need to get this off my chest. On Easter my friend from school killed herself, I wasn't there for her and had no idea she was upset. I should have known because I have been in that same place before where I just wanted to die. The worst part is it hasn't even been 7 months since my last friends suicide at school. I have family dying from suicide left and right and can't seem to help anyone. I feel lost and upset that I can't see when other people are hurting, I should know if they are my friends  when they are upset or faking a smile. I should know because I'm like that but I don't know I can't tell if they are hurting. My dad laughed when I told him she was dead because of something I said, he told me to pray and at this point in time I'm at school and just found out. I reply back to him "it won't help, she's already dead". My dad than laughed at the message, it's five days after the message was sent and he continues to bring it up. On top of it me and my boyfriend just broke up today, I'm so lost. I'm not happy I'm not sad I'm just neutral. I'm numb to everything and everyone at this point in time.