I struggle a lot with shame. If I accept that what happened was abusive it feels as though it changes the meaning of everything and everyone around me. It feels as though it would confirm and solidify all the things I feel about myself, that I should have done more, known better, that it has damaged me, altered me, that I am wrong and bad. It is too painful to have all these things confirmed as true.
This seems really super important to deal with. The fact is, you are NOT damaged are wrong or bad, and you are not damaged, and it wasn't your fault. (You simply don't have such power and control over other humans and their choices and actions.) These are very common distorted thoughts that most survivors think. They internalize the abusers messages as a way to survive the trauma... but when it's over, it's no longer helpful to think these inaccurate things.
I can really relate to how it can feel like one would be damaged if they admit they were abused. For a long time, it made it almost too real for me to say the words. It took me a long time and a lot of practice and skills building before I could say the words. When I did, it was hard to hold on to self acceptance. It still is hard sometimes, but it gets easier and easier.
You. are. not. worthy. of. shame. Your abuser is. And your abuser WANTED you to think these horrible things.
Instead of diving the abuse, maybe it would help to talk about your fears of what the abuse means about you as a person and work with your therapist to begin to disagree with your abuser(s) (they are perps of horrible trauma anyhow and not with agreeing with.)
Perhaps there are things you wish you would have done differently, and some small amounts of guilt are natural - but guilt doesn't shut people down or define people as a person. Guilt fuels change. Shame just keeps us stuck - like you are experiencing. It's not yours. Perhaps you could ask your therapist how to let go of the shame and self contempt, and to begin to give it back to the abuser.
I did make some progress last year in feeling more able to say it was abusive, that I wasn't in control but as soon as the sessions stopped I wasn't able to sit with those painful feelings, so I started building the wall of denial back up. I know I shouldn't have but I hated how it felt without it.
That makes complete sense. Messages that we internalize from trauma are internalized with life and death levels of importance. In therapy, it's not life and death, so it takes a lot more repetition of hearing good positive messages and time to learn to internalize those messages of acceptance in a way that it overrides the past messages. When the therapy ended, the support ended, it makes sense you built the walls back up. It probably fell like hell without it. And that's ok. You coped the best way you knew how, and you are taking the brave steps to engage therapy again.
You have a ton to be proud of. The fact that you let the denial come down in the past is a really good sign you can do it again. And again. And it will get easier and easier with time and practice.
Healing and acceptance isn't so much a place that someone finally arrives at, it's usually a journey. With ups and downs and setbacks and steps forward.
You are taking great steps forward. The more you can celebrate every small and big victory, every step forward, the easier it will get to take other steps forward.