I found the idea that a therapy is involved very interesting but...
I'm still confused, is there a psycho or not? Even if at the very end we learn that it's just an hallucination (we've seen this before many times, and very well executed a few times), it's not what is important now, you don't need to spoil this kind of ending, but the logline should let us know what the movie is about. A man and a woman who fight? They fight together against a psycho? Against a mad therapist? Against many supernatural being who haunt the forest? Is the therapist a deus ex machina who set a trap for the couple so that they will be pushed to fight each other?
One more thing, usually there is only one real hero, not two. Even when there is a team, only one person is the real hero. Your movie seems tricky because you have two heroes. Even if they fight each other, the audience needs to take one side.
There is one more tricky point: you should make clear also if the couple is 'broken' and their experience in the forest 'heal' them the hard way, or if it's two lovebirds who become rabid dogs. Usually, the best is to imagine the story that allows the longest journey... if you have a broken couple and they become rabid dogs the journey is shorter...
About Blake Snyder, let me know if I'm wrong but he's the teacher who is the most successful as screenwriter. All the other gurus hardly wrote one single feature lenght movie... Anyway I don't think that it's really necessary to be a screenwriter to teach screenwriting. Maybe Snyder is not the best, but not because he has a short file on Imdb (with this criterion he would be the best!).