I read this script and enjoyed it, but I'm... befuddled.
PLOT SPOILER:
I like the characters and I was interested in the story and although your plot is logical, in its own way, to me it was disappointing. It's believable that Jane could lose hope, but I felt like you, the author, gave up on her too soon.
For me, from the point that Dr. Parker invites Jane back to her house the story begins to fail.
It seems peculiar that the Dr. would be foolish enough to let her former patient stay overnight, unwatched, in her own home -- peculiar enough that the audience might wonder if Dr. Parker really exists, and then when we hear from presumably reliable third parties that the Parkers are the victims of a crime it's more confusing than shocking.
I mean, the world that Jane lives in doesn't seem worth living in -- the "good guys"; the Dr., the police, Doug, are well meaning but dull witted and flat.
So when Jane struggles with Ruby, at the end, I wasn't really rooting for either one of them, and when the other personalities give them the final push, it seems like exhasperation more than anything else.
The point I'm trying to make is that your characters are too good for that kind of ending.
I really think that if Dr. Parker is a foolish but well intentioned character, she and her husband should be spared (the blood on Jane's hands isn't real) or...
the Dr. Parker that Jane meets at the diner is imaginary and the Real Dr. Parker steps it, at some opportune moment, and contributes something important to the plot line...
I don't really mean to presume to tell you how to end your story, but I think it's too good to wind up so fast.
It's a logical ending, it's just not good enough for Jane (and company).
Just my two cents.