Couples counselling - What to expect?

Would like to hear the experiences from people who have been through similar situations and been to couples counselling sessions.
I (43F) and my partner (50M) of 16 years have our first couples counselling session booked for next week. For a context, my partner recently decided that he wanted to go separate ways due to intimacy and resentment issues (no affairs involved) and we’ve been living separately for about two months in different cities due to our work now. I consider him the love of my life and want to rebuild our relationship, but he is adamant that we can’t turn this around.
I want the session to be an opportunity for us to be honest with each other about how we’ve been feeling and what we’ve been struggling in recent years. But deep down, I’m so desperate to get back with him and I am worried that he might see the counselling session as my desperate attempt to convince him to stay.
If anyone has been in a similar situation/position, what worked/didn’t work during/after a counselling session? Any insights would be greatly appreciated as I don’t know what to expect and am quite nervous right now.