I can only talk from my experience since bpd clinical picture is heterogeneous and we all have different sets of symptoms (although we fit into general dsm criteria)...i am not familiar with dbt (not available in the area i live in), i am applying basic cbt and it has been relatively useful...i understand you are in great emotional distress and i know it can be very hard at times...every day is a battle for me too, some days are better some are harder, and i have made it my "life mission" to find strategies and tools that work for me (trial and error). symptoms are constantly shifting and i try to find best ways to cope. it requires effort, and yes i'm tired. But for me giving up is not an option. I'll give you an example...years back i had excessive panic attacks and have developed severe agoraphobia (at one point i couldnt leave the house). after period of desperation i decided to do something. i have read a lot on the issue, talked to my therapist and made a plan. i have gained theoretical baseground and tools but needed to put theory into practice. I had to learn to stay "calm" during panic attacks and have walked 50 m longer every day dealing with great fear. It was hell, it was the unknown, i couldnt know if it was going to work, and i had to do it by myself, alone. But i kept going and it took me some (longer) time to actually walk around without severe anxiety (this was my way of dealing with the problem, other people might find different approaches more useful)...but what i want to say, is that the effort i put into all that was essential to the end result, and the strategies and skills i have gained through that experience are now helpful in many different areas. Dont give up on yourself, every micro step forward is a true victory!

p.s. excuse my english (grammar mistakes), it is not my native language