Hi lighthouse,
Welcome ,
I'm sorry that you are going through so much hopelessness right now. Living with someone with BPD can really wear us down and cause us to have difficulty in our lives. My H also has a new drama everyday. For me sometimes I'm glad when he is focused on someone else and not me.
You've found a great place here. One thing to remember is that you can't fix him. You can't change him. You can't make him do anything he is not ready to do. You can only change yourself. We have a lot of great resources on the right side of the page.
You mentioned that he is in counseling. Is he seeing the right type of counselor? For someone with BPD, the type of T that seems to work well is DBT therapy. Could your H look at finding a new counselor or specialized in this therapy? What about you? Have you considered getting counseling for yourself to help you in your own struggles with the relationship? I know for me T really helped quite a bit.
To get you started here is one of our workshops on enmeshment and co-dependency.
https://bpdfamily.com/message_board/index.php?topic=111772.0