Aha! Go back and read your last comment again.
didn't cut you. YOU
You are confused. This isn't about her, it's about you and your reactions. Until you fully understand what causes you to hurt yourself this way, and how to stop that behavior, you need professional counseling. Start looking for a good counselor RIGHT NOW. He/she will help you sort out your feelings of confusion and self-destructive urges. If the first counselor doesn't help, find another. There IS help out there.
To answer the title of your thread:
NO, hurt feelings cannot kill you.
You can kill YOURSELF over hurt feelings (among other things.)
Don't do that. Feelings change.