I do not have experience with this - I am only fluent in English (I know some German and Spanish, but definitely not enough). Although I can't relate on a personal level, what you're saying still makes sense to me. I know this wouldn't be an exact solution since your therapist only speaks English, but I wonder if it could be therapeutic for you to at least express certain things in Japanese, then repeat them in English. That probably wouldn't help with the connection, but it could feel good to say those things aloud in Japanese anyway. Your therapist would not understand the words, but she would nonetheless bear witness.

I don't know, just an idea.