You asked what you should be doing. I agree that right now you really shouldn't be doing much other than relaxing the tension and caring for yourself. I applaud that you are posting frequently and managing to meet the basic needs of your children.
If I had one suggestion though it would be to make sure that you're sending affirming vibes towards WAH. This doesn't have to be over the top "You're such an awesome dad!" But it could be something simple like "They're lucky to have you as a dad, happy Father's Day", or just some non-verbal communication like you smiling when you see him with the kids.
This isn't trying to 'win him back'. This isn't dismissing the pain he's caused you. It's a matter of deciding today and going forward what kind of person you want to be.
So I think a good habit to get into would be to at least be aware of how much of what you're writing and thinking and talking about with others is negative. Maybe even try to find some things that are positive as well. If you can't see anything but disapproval for WAH, then can you kind of see why he might want some space?
It really is ok to vent here. We get it. I'm not saying you can't validate your feelings and get some support for the pain you're in or the situation you're left with. I'm just getting back to your earlier question. You can write here what you need to get out. What is more important are the messages your expressions and tones and responses and gestures are sending when you interact.
For what it's worth I'm glad you let him see the kids today. I agree with the others that a schedule will be needed in the future and it can't always be come and go and bend over backwards to accommodate. But this is the very early stage of a very unstable situation. It's a good idea to take it slowly. And trying to take unilateral control of the situation by making demands or laying out a schedule without discussion might not be the right move. Even telling him that HE NEEDS to give you a schedule isn't my recommendation. I'd just let it sit for a few days or a week or two. Maybe he'll bring up the schedule idea. If not I'm sure we can help you compose a DB approved email that isn't controlling or demanding. Something that starts by validating his desire and rights to see the kids, and appreciating that he is making them a priority.
Right now things are a little unfair in his favor. I get it. But this is very short term. No need to score keep. If this proceeds to a true separation and divorce you will have your schedule soon enough. But I don't see a reason for you to be the one to escalate it to that stage so soon. Let go of the unfairness of it, focus on the positive that he is seeing the kids and speaking to you, and get through today.
Hang in T0.
Me:38 XW:38 T:11 years M:8 years Kids: S14, D11, D7 BD/Move out day: 6/17/14, D final Dec 15