How do i express needs to someone who isn’t capable of hearing them?

I feel like my whole relationship with my Q, I cannot express a simple emotional need and be heard. He either dismisses me, gets mad, gets overwhelmed, says it’s ok, wants to talk about it later, or pretends to hear it but then violates it slowly over time. He does whatever he wants. I feel so anxious even though I have pretty strong boundaries. His behavior impacts me / the whole family even though my life is otherwise in order.

He is barely functional: seems very sweet but isn’t able to maintain close relationships without conflict, financially barely keeping it together, sober for months at a time but generally emotionally erratic. I just hate worrying about him, though i know that won’t go away. But I know if I express my feelings or how this all impacts me, it won’t go anywhere. He is “living his best life” while others worry and he is a perpetual victim.

Is the next boundary absolutely no (not just low) contact? Has anyone done this, and if so, how did you overcome the guilt? Was the peace you felt worth how hard it was to do?

I am in program and have a sponsor. I just don’t know how to navigate this. It helps to share and hear others’ insights and experiences.