Well, as a general thing, you'd look at severity of episodes and frequency.
If you get a reduction in either, the med is working. Some issues are harder to medicate, often because a lot of meds are essentially a stab in the dark when the underlying condition isn't well understood. Since you listed a lot of things that aren't your diagnosis, chances are that whatever the diagnosis is, isn't going to be well understood. Not that most psychiatric issues are well understood to begin with.
Since what you did specify is relatively poorly understood, and isn't psychiatric in the same sense as bipolar, it really is going to be a matter of trying shit until something helps. The real treatment for relational trauma is talk therapy in one form or another. The meds are there to give you time for the real treatment to work. It's like taking aspirin to reduce pain while your body heals.
Dbt, unfortunately, takes time. A lot of time with more severe issues.
I guess what I'm saying is that you keep trying meds and hoping one helps. That's all you can do. The meds that might help as a breakthrough option (like benzos) can't be used long term, and actually interfere with treatment when used, so the most you'll get in that regard is something for a few days.