I don’t know how to deal with being hurt deeply

In life, when you love and only get hurt in return. It just hurts. And there’s a moment of weird useless I wish I didn’t exist feeling...
Sometimes a moment of anger, grief, hatred, humiliation? wondering what I did that was wrong, then wanting to blame someone else. And finally some sense of relief mixed with stupidity? Then -it’s gone. But in the moment... those moments were hours. So weird.