I’d also add I tried DBT last summer for about three sessions and found it triggering, because several members of the group (who had BPD) reminded me very strongly of 2ex. Plus the whole being bossed around and infantilizing approach reminded me of him too. The triggering nature of DBT is pretty well known.

I’d be concerned about that possibility if I were your therapist. Where I think he is right, though, is something needs to change. Three sessions a week with him and out of session contact don’t seem to be helping you much.

If you wouldn’t start at this place for 9 months since they have a waitlist, why not fill out the paperwork and then find something else to try in the meantime? EMDR, meds, whatever seems worth a shot.