Honestly I'd just say he was weak, and overly delusional and psychotic maybe..
I mean, I think almost everybody has 'fallen in love with a ficticious charecter that doesn't exist at some early point of their life, and feel a bit depressed about it, but never to the point of losing control of our own lives like he did.
I wouldn't judge him for that, maybe he simply felt emotions too deeply and felt like he'd rather die than not being able to spend his life with his love.
Who knows, maybe he knew something we dont, maybe there is more after death that we don't know about, like an afterlife that you build and create in your mind..
A dreamer and optimist would say he's with her now, finally happy.