How happy she is about it feels like a façade that she's putting up, even to herself, though, so she doesn't break down.
Basically, it's a decent action, but how she's going about it is incredibly unhealthy.
Oh yeah, we're just waiting for the other boot to drop now, because while it is healthy to cut out toxic people from your life, it seems like Dora is about to do it in the worst possible way. I mean, from the looks of it, she hasn't spoken to Sven about this and from what I can see, Dora hasn't spoken to her parents about her therapy, let alone her problems with Sven.
Dora might think she's digging herself out of a hole, but my guess is, she's just making it deeper.
OK, registered just to post this: The most toxic person in the comic is calling someone else toxic? Seriously?
I wouldn't call Dora toxic, she's someone who has not had the easiest path in life and not possessing the best idea of how her actions have consequences and tends to jump before she looks. She's had to deal with a lot of rejection in her life and so it's coloured her view of the world.
Sven, on the other hand, is a guy who has always breezed through life, been the "perfect" older sibling to Dora (perfect in the sense that he could do no wrong), writes crap country-music songs but still makes money off them and felt that Faye should have reciprocated when he announced that he loved her, despite the fact that his own actions caused the dissolution of his relationship with Faye and, more importantly, she is now in a relationship with another person. This is probably the first time he's been rejected and he can't actually deal with it. Add onto that his encounters with the other members of the cast (save for Hanners), the guy is a manipulator, a very toxic kind of person.