She's squeezing the life out of you (and not in a good way).
Yes, well put. That is exactly what she is doing, like a parasite, living off of Lou's life energy. She would be so much happier if she could have a life of her own. Stop enabling this Lou. Deal with your guilt and your fears of her leaving you.
If you have to make her stand on her own two feet it is only for her own good. She won't die. She will be scared, but once she sees that she can survive, it will be the best thing that ever happened to her. She will be able to return to the living.