I was rather shocked that you don’t think what’s happening in your home is traumatizing for a young child. Anyone with any kind of training in the area of child development/child psychology, will tell you what’s happening in your house is traumatizing for your children. I can ensure you.

It would be traumatizing for an adult, let alone a child that young.

I am also surprised that you don’t think you have anything to discuss with a therapist. You can simply start by describing yours and your children’s life the you described to us, current life and events from the past etc Good therapist will find things for you to work on with information provided

At this point I’d probably stop worrying about what your partner he does in his therapy and focus on the needs of yourself and your kids and their rights to live a peaceful life. Please do seek help for yourself and your kids