I'm surprised they have you not seeing your "T" while in the program. Do they have you seeing someone else for outside of group therapy? That's what I had to do when I was in DBT.
Honestly, I thought that, for me, while some of the information was helpful, most of it seemed like stuff I already knew, plus, it wasn't exactly cheap to see a therapist 4 times a month plus go to group 4 times a month - even with insurance.

That said, give it a try. It may work for you.