I see a lot of people who understood this episode and many are saying it was filler or flat or unrealistic after what they saw from Rue in the previous episode. The answer is simply that yes, Rue as most addicts can go through a day or any period of time that they are completely out of control or searching for their drug so as to not be sick, and turn it around quick when they either hit bottom or get their fix. In this case it was both and she was given medication to not have withdrawal symptoms so she went back to her normal self. I think people that don't understand addiction say that she was so bad to people she loved that that is just how she is, but that is not true in most cases. She was being controlled by the need to do her drug and would stop at nothing to get it, but that is a symptom of addiction and not oneself.
Besides that it cleared up the whole Jules and her disk being out there and Nate and Cassy seem to be as dysfunctional as Nate and Maddy were in their own way. Fezco and maddys sis seem to be getting close , but it looks like the cops are going to raid him in the next episode or finale.
So I disagree that it was a flat episode or filler. It actually sets the stage wonderfully for what Rues future is going to be as far as her addiction. Remember at the end it looks like she will not be able to enter an in patient rehab because she already went through withdrawal and is on a anti withdrawal medication like methadone. This could potentially be catastrophic as an addict needs time in a rehab and not just a few days and some medication to really have a chance at getting clean. So much happening it's hard to say this was a bad episode or not on track with the story. I say excellent depiction of drug addiction and it's effects on a family.