Mighty, What you are going through is very, very normal. It's more difficult the second time around when the crisis person actually has reached out and is trying to reconcile w/the spouse and then they skip a beat and return to the Land of Oz.
Your mind is on auto pilot and it won't turn itself off because you are thinking about him and the ow a lot. You've had a few triggers in the last couple of months that have kept these thoughts going, i.e., Mother's Day, Memorial Day and Father's Day. Even the phone conversation that you had w/your BIL sends your mind in a twirl because it keeps things "fresh and breaks the scab that is trying to heal your heart". Work thru those feelings and then try to let them go.
I hope that you have some nice things planned this week for yourself. You owe it to yourself to do something fun and different for yourself. Make a list of the things that you would like to do, but never had the nerve to do. Then select one of the items and really think about doing it.
Sending you positive thoughts today.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.