I think the DBT thing sounds like a great idea, and then telling your mom you are seeing someone for an ED so the insurance can pay for it.

I just started DBT this week (although haven't learned any of the skills yet, just an initial appointment). My T also decided once a week psychotherapy wasn't enough for me and recommended DBT. At first I was hesitant (well, actually I kind of didn't have a choice, b/c she pretty much told me the only way to see her again was if I did DBT), but I get what you are saying about it sounding cheesy. I also thought it sounded very gimmicky.

However, I looked into it some more and it really has been proven to be very effective with self-harming behaviors. And I think the skills sound really useful to learn.

Growlycat is right, you should do this while you are still on your parent's insurance so you don't have to pay. Plus, DBT can be used for binge eating, so it's not like you'd be lying.