Hi Pie! Hope you're feeling better today. The way I tried to control my thoughts, was to work through them constructively, especially when the STOP didn't work. Of course, my H never left the house, his OW was far away at that time. So, sometimes, I had the opportunity to tell him exactly how I felt about his infidelity. But, I don't think it would work with you ... your H could just leave, whereas, mine had nowhere to go. And, is still here, after 6 years, apparently broke contact with OW before she moved closer. Yes, I know that sounds unlikely.
Give yourself a time limit to think through whatever is on your mind, then give yourself a reward (a treat of some sort), and start thinking about something else. Worth a try, anyway.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim