My background masters-level training is in systems training and couples work is about being able to work with the couple as a whole. It is recognizing and identifying that even disfunction in a relationship serves a function. Couples get stuck in patterns and it is helpful to be able to identify the patterns but then it is important to learn skills and move the conversation to a deeper level of understanding unmet needs, dreams, goals, and desires. When trust has been seriously broken, it needs to be recognized that forgiveness is possible but that an examination of all that was involved in the breaking of the trust to ensure that it does not become a pattern in the relationship. The modalities I would use would be Structural Strategic systems therapy, Emotionally Focused therapy, the Gottman Method, Satir Communications, and more to improve: couple communication, conflict resolution skills, address negative interactional patterns and improve resolution skills.
It is critically important to say if you are coming for counselling because it is an abusive relationship, I will not do couples counselling as it can increase the abuse.