(((((((((((zoo)))))))))))

That is a tough situation. For me, it's a huge RELIEF to just be honest about that sort of thing. Not having the money sucks, but having to live with (and try to keep up with) a lie feels even worse, at least for me.

Can you apologize, explain the situation, and give her what you have? And then maybe set up a timeline for paying smaller amounts until the rest is paid off? It's usually easier for me to come up with $20 than $200 (or whatever)

I don't know much about DBT, but it seems to me that thinking this through, deciding what's important to you, and coming to ask for help are all really, really good skills.