Your situation is oddly like mine. I've been desperately trying to sort it out in my head... maybe some of my thoughts will help.

I was married for 10years to a bipolar man who refused to get any kind of medical treatment. I did not know he was bipolar when we married. Soon enough the ups and downs began to cycle and I didn't know how to respond... kick him in the *** while down or tell him he was being an *** while up? He also refused to find work.... prob. because he knew he could not hold a job. When down, he stayed in the house and never came out and said everyone hated him. When up, he posted 25 times a day on Instagram, ran all over town like a grandiose, superman wild man, could not even hear what I was saying. I grew to hate the up phases.

I felt I could not kick him out bec. he did not have one penny to his name. When he inherited a little $ in Jan. '20 I striked while the iron was hot and found him a place and he moved out.

A month ago, he told me he has a new girlfriend. Something about it triggered rage and hurt in me. I've worked with my therapist on it. Here are some of my revelations:
-I'm a child of an alcoholic and will do anything to hold onto a relationship, even an unhealthy one... I dread abandonment and being alone.
-I'm horribly codependent and should have kicked him out after a year when he refused help and work. I held on... stupid.
-He, like your husband, has not given me one thought... he is blissfully in love. He has no empathy and is a narcissist. I am near suicidal with depression and he could care less. I think it's because he is so happy to be out from under my scrutiny. He gets to start all over with someone who does not yet know how horrible he can be. Also, I've heard that SHE is bipolar too. So she will impose no expectations.

Even before he moved out he started hanging out with some young musician girl, telling me they were just writing songs together blah blah and that I did not understand the musician world. Um, NO. I did kick him out but he had nowhere to go so I let him come back (stupidly). Then found him that place.

Though I know I let it happen, I hate him for taking advantage of me for 10 years and not feeling one bit of remorse.