How do i know it’s over?

15-year relationship F38 M45 in a dead room. Autistic son. My husband suggested couples therapy, but he doesn't schedule it. He refuses sex, and when he does, it's unsatisfactory. He doesn't kiss me or hug me. I asked him what the problem was, and he said he feels it's just for convenience. I want it to work, but it seems like only I want it. I'm tired of being rejected and feeling alone. He said I don't love him, that we need some time for ourselves. When it happened, he drank too much and went to sleep with our son. He resents me for taking more care of our son than I do, while I work much more to pay the bills and treatment.