pmbm sounds like you had a breakthrough even if it was at the end. Sometimes writing things down in a notebook gently pries the door open. At least your therapist is staying calm. Another thing that may help is recording our dreams.
Talk therapy can dredge up old unresolved issues.
Sometimes yoga (youtube beginners yoga adrienne) can take us beyond the pain. It does not have to be a battering ram approach but can just be a gentle trickling around the problems.
healthy diet helps mood swings. eating ever y 3-4 hours - high protein low carb no sugar helps keep the rollercoaster on low levels