It might help to realise that your difficulties within the relationship/attachment with the therspist IS the trauma work. It has been proven that complex PTSD is an attachment disorder: neuroscientists have found that only those with insecure early attachments will develop full blown PTSD. So it is quite normal that you keep stumbling upon attachment difficulties within your therapy. Being able to recall the trauma with a witness to help is very healing, but the main healing is within the attachment to the therapist.
It is within our primary attachment to mother that we internalise the tools to manage difficult events/feelings. The therapeutic relationship acts much in the same way - it gives us the means to cope with the trauma and to better regulate our feelings associated with it. It has been proven that a longer term relational therapy allows neural pathways in our brains to grow - that's how important attachment is. Psychotherapist Margaret Wilkinson, who writes extensively about attachment and the brain, says ' it is mother who grows our brains.' A relational Therapy can do the same thing. That's how we can heal from trauma.
Moon