How do I not let this control my every thought?

[Sugar and Spice]

Travis, the bitterness is something that you work through and it goes away in time. I too obsessed and worried myself sick over something I ultimately had no control over and wasted a lot of time on what-if and maybe ifs.
As hard as it is, focus on you and your boys, only. Let your W go and live your life and be there for your kids. W is going to do whatever she is going to do and that is just the reality of it. If there was a way to stop it or make them see reason, we would have all been let in on it by now. She is all wrapped up in the A and the fog that comes with it, which she exhibits by giving no thought to anyone but herself.
If OMs children are a real and possible threat to the safety or well being of your sons, then steps should be taken to ensure that they are not placed in that sort of danger, have you discussed this with your atty?
I wish I had some better advice to give you, but what has been said by the wonderful people before me holds true.
Focus on you and the kids. Don't pursue her or try to engage her in any type of conversation other than your boys. Is there anyway you could talk to your boys at her Dad's, without having to speak to her? Have you looked into a temporary custody agreement that would include practice/games? Would she be more willing to allow him to play if you would pick up and return son or is it more of a control game?