H..... I will do my best to help you out as I am going through this exact same thing as you know. My W and I are following a recommended parenting plan spelled out by the state in which we live. Since we are a 50/50 split I get them M Tues and every other weekend(yes it [censored] but that's what I get). You need to attempt to get this in place as soon as possible so issues like you are dealing with don't pop up. When my W moved out(on XMAS eve) she left the house at 7:30 am with my daughter to help set up her new condo, I had no idea where my daughter was as my W and I had agreed on the kids being with me all that day.
The reason I say this is because my wife never counted on me becoming closer with my kids than I was at BD, she has in some ways pushed away at them as well and now she takes every chance to spend more time with them or at least have them in her presence. So, get the parenting schedule set ASAP so you know your time! No more surprises, it's not fair to the kids!!
And you need to learn this word,,,, NO! use it! I have learned to use this lately and man is it a powerful word. You know we both suffer from NGS so learning how and when to use this even with our kids can be very helpful to you! I agree with Sandi on this as well, we can't can't baby our kids in this and continue to keep this from them, they're smart, they see right through this madness. They see who has the sh*t together! Stay strong brother you're doing great!