Hi. If there is any way you can help me, I would greatly appreciate it.

I am looking for the title of a movie that I saw on either IFC network, Lifetime, or Sundance channel.  I believe I saw it in or around 2098-2008?? From what I remember, there were no famous actors in it and maybe only had 2-3 people in the movie. I will
give you a description from what I remember happened.

Basically, it starts off with a young woman (blonde, I think…looked maybe a little like britney murphy??) in an apartment and I think she is fresh off of a break up with a boyfriend. Anyway, she lives alone in an apartment and might be some type of college student or grad student working on a thesis?? Somehow, a detective gets involved, I think her ex was reported missing or something. The detective stays with her in the apartment (I think because she was getting creepy phone calls) and the two eventually become involved romantically. I’m pretty sure the whole movie takes place in her apartment building (kind of seemed like a very low budget film). I also remember there were like electricity problems and she would have to go to the basement in the building to fix it. It ends up with a twist at the end that she had actually murdered the “missing”
Ex boyfriend because I believe she caught him cheating in the basement of the apartment building (maybe in an abandoned old pool??). And I think the other twist is that the guy who was the detective really didn’t exist, she was just imaging it.  All of the pictures in her apartment of her and her ex boyfriend had his face either cut out or a red X or something over his face, but at the end you see that the “detective” is the one in the pics with her.  She had imagined this whole scenario with the detective the whole movie.

Any help would be great. I’ve been trying to figure this out for years.

***nobody famous in this movie