@Shodan
It was very similar with me except we did not talk for a long time at all. Last year in Jan something happened that was the last straw for me and i told my STBX that I want counseling. He told me he is willing to work things out but does not want to talk to strangers about his personal stuff. Well in a way, that was it for me. I started counseling alone but slowly, after only few sessions, I realized that my marriage is over.
We kept going during pandemic as I did not want to end it during those uncertain times, but unfortunately one after another bad thing kept happening to us and I soon realized that it will never be "good time" for it. One day I just said it, I am sorry but this is not working out. I am not happy and no matter how much I tell you, you are not changing your ways, in fact I do not think you can change. I wanted to give us one last chance to do couples counseling, b/c we really do not know how to effectively communicate but you did not want to do that. Funny thing is he was shocked, he said he did not think it was "that bad" even though I kept telling him, "you know our marriage is in crises" and he kept saying, "yes, I know". Wtf!
I am not sure what it is with men but they are so complacent. There are a lot of threads here on MN where women say that they told their husbands it is over and they still carry on like nothing happened. Especially if you still have sex with them it seems that is all they care about.
OP I know that a lot of people will tell you that you owe your DH explanation and that you should talk to him and explain and give examples. I say, no, talking is for trying to fix things, for the times when you still believe that relationship is salvageable. Once you decided it is over, do not get caught in talking and explaining. B/c bottom line is the same, you are not happy and you want out and that is that. Keep you conversations short and sweet, be respectful of his feelings and as gentle as possible but do not engage in long conversations. I am telling you this b/c I am the same as you. My STBX is very intimidating and it was always hard for me to talk to him about anything important, he will always get it his way b/c I could not fight. So once I was SURE I wanted out, I literally erased all other speeches from my mind and only kept simple and clear thoughts. "I am not happy and I want out. Yes, I am sure". And one more thing, do not say you are sorry, b/c no matter what the reason for the break up is it is not only your fault and you should not take the responsibility. He will blame you anyway. I also tried to avoid saying this to my kids when I told them we are breaking up. I did not want them to think I thought it was my fault or that i feel bad about it (which I do in fact a lot), b/c especially for the kids, I think is important they know that this is your decision and you are "happy" about it.