Stop, breathe, and know that it is going to be ok. This is going to get better. It will hurt less. You and the boys are going to survive, and in time thrive. I am so happy you found a lawyer you like. It makes all the difference.
DO NOT say anything to him about what you "know." That is the same old fight, same old dance, same old dynamic. Limit the conversation to what you talked about with the lawyer. That it is not working, that he has until Friday, that you are changing the locks and he can see them on a weekend day until he has appropriate accommodations to have them overnight (don't get into the details of what that looks like).
The need to tell him about the concert thing is again you need to let him know you are smarter than him. I get it, I used to tell my H everything I knew the second I knew it. Now I tell him nothing and feel that I have much more power. I love that he has no idea what is going on here.
Do not in any way suggest or hint that the filing or service are coming. Let him think you are meek little T waiting for him at home. In that moment you will regain much of the respect that you have lost in this process. Only time will tell what he does with it. You cannot control how he responds.
I know you don't feel like it, but you really can do this. You already are.