Amelia reacts here to an intervention staged by her friends. She isn't exactly receptive to the idea when first presented with it.
Addison is just trying to help Amelia. But the latter lashes out during this intervention.

Private Practice Season 5 Episode 8 Quotes

I know that you have a family here and I see that you're destroying it. If you continue down this path, you won't just go down alone, Amelia, you'll take down all the people that love you.


Fine, I'll be your drug dealer. I just want her back.