Hi, OP,
I’m second guessing myself like have I let the best one ever get away? What have I done? Like basically this is another way of saying “you’ll die alone/ I’m so wonderful and I’ve been so good and accepting of your issues and if you don’t trust me you’ll never trust anyone and die alone”
It's expected. He's trying to make you second guess yourself. The fact that you see this already is a plus on your side.
None of what he is saying is true. I'm not even saying that he thinks it's true. He's venting, blaming, has probably had it up to here with his kids lately. None of this is your fault.
You haven't asked him to come back. He thought you would.
You haven't broken down into a million pieces. He thought you would.
You're having quite a nice, relaxing time without him. He never thought you would.
He's panicking. It's not about you, it's about the fact that he is moving into pain and acceptance and he wants it to all go away. None of this is your problem, your fault, or your concern.
He is showing you who he is. Blaming, deflecting, DARVO. Believe him.
From what you've said, you are doing quite well so far. Keeping doing that and ignore all the noise. Because that's all it is, noise.
If you want to block/mute the noise, that's up to you.