mira.....I, also, am concerned for you and your welfare, given what you have shared, with us.
A basic fact-----He is their "client/patient", and, the bottom line is that HE is their primary concern----not You. I am not saying that they wouldn't want to hear what you have to say---but, your happiness is not their main concern.
It still remains, that, you are the one who has responsibility for your own happiiness and welfare, and it is your own job to speak for youorself!
You do have rights.
You have the right to not attend the session at all, if you decide not to.
You have the right to tell the facility---the case worker---that you have suffered a lot of verbal abuse and physical abuse at your BF's hands. In fact, I feel that it is essential that you do so.**************Even if the case worker will not give you any information about him----you can, legally, tell them any information that you are of a mind to.********
You, also, have the right to end the relationship at any time that you want or decide to.
If you do decide to ttend the session----do not let him or the case worker intimidate you. You can , also, call an end to the session at any time you might want to do so.
You have as many rights as he does.
On another note---I think that this would be a good time to line up a counselor/therapist of your own. I strongly beldieve that such person MUST have a specialty---meaning, lots of experience in treating victims of abuse----any kinds of abuse.