Oompa,
She might be saying "I love you" because she really does love you. Couple that with seeing self-destructive behavior, and she is probably scared shitless for your life. And add in a heavy dose of cult brain washing, and she is probably a mental zombie.
I know that the religion was your biggest commonality, but you need to inventory your feelings for her. Do you still love her, or are you just experiencing reflection on the supposed good times? Or are you expecting her to change her beliefs to correlate with yours now? It may never happen. You need to figure out why you are not saying ILY to her as much as she is to you.
Just a thought, from somebody that has been married and divorced three times. What the hell do I know?
JK