So heartbroken

I know everything my husband is doing is wrong. He moved out almost 2 years ago. I've always known he's selfish and thinks about himself more than anyone. He is also has good parts too. We are best friends. Probably why this is so hard. He has said he's filing divorce over the 2 years about 10 times and then just doesn't go through with it. Meanwhile makes me think we are going in the right direction and then it's heart break all over again. I thought counseling was helping and then he said we didn't need it anymore. Married 16 years, together 17. We never had a bad marriage, normal issues. I watch videos, read articles. I get it, if they aren't fighting for you, putting you first, etc You should walk away. I know this, but letting go is so hard. The heartbreak is devastating. I feel like he's just bored with me. Maybe mid-life crisis? He will be 50 this summer. We each came together with a child and they are grown now. We are such a close family. And he doesn't understand how we would just not see each other and talk if we divorced. Why would I though? Someone I trusted just walked away from a good thing. I've gone all in with trying to work it out and he just works and works and doesn't face the issues he is struggling with. Add on shelter in place above all else. I have ok days and very dark days and I'm so lonely and sad. I guess I'm to nice and love to hard. But I took my vows seriously. Thanks for taking the time to read my rant.