Confused & mix messages part 2

[Cherry]

Think I am undoing all my good work. He ended up getting me stressed picking a fight so I ranted about the OW. He claims he has felt like this since before OW got involved. He goes out of his way today to message me which was in a way he knows would wind me up. Telling me he's going to be late back ( he never usually messages me at all- especially to say he will be late) and its up to me if I believe him or not. He then tells me he needs to stop before he says something he regrets.
I don't actually think he has any rights to call any shots right now.
If anyone has any guidance on how to handle this I'd appreciate it. He said we will talk when he gets back, but to be honest the way I am right now I will rant and rave and ruin all of my hard work.
Any tips on how to handle this?!
I do want this to work but I know that things need to change. Boundaries need to be made, and I shall make it clear I will in no way support his divorce.