I don't agree that this is on the therapist - perhaps giving his way of working a shot could be something to try.

Attachment is not the end all and be all. Is the goal to do something different in one's own life or is the goal to just sit and moan about one's parents or others and how they did one wrong and get petted for it? I mean either is okay if that is what one wants to do.
I found therapy useless in any sort of practical way other than when needing to vent about my person and the absurd medical machinations. I don't understand the attachment stuff at all or even why one would want it -so again context for my approach.