Dantalion is about persuasion, who could help her be open minded and communicate better, but it looks to me like the real issue is the hurt she still holds. You might like to try a healing entity for that. Marbas or Raphael are commonly called.
Couples therapy is a great idea all round and you can work with entities to maximise it’s effectiveness, and you’re already working with Dantalion for that. Paimon should be good too.
The Angel of Lost Things might be able to find the lost trust… don’t know but that thought just occurred to me.
From this list, Foras and Botis could be helpful to bring understanding, courage, and help you get closer.