So M, since you're concerned about the holiday traditions and how they'll be different this year, why not plan for a change. For instance, you said that you and H normally take down the tree on Jan 1st. Plan on doing it the following weekend, or take down a little each day. Tuesday the ornaments, Wednesday the lights, etc... If you plan on a change then when your normal way of doing this didn't happen, you had a new way of doing things planned for a while.
And regarding the tape you asked H to return. You have no idea if he watchted it, if he watched it with OW, or not. Stop speculating. You're driving yourself nuts with that. Use the stop sign trick. Personally, that never worked for me. I had to physically start doing something else to get my mind redirected. But do what works for you to stop those thoughts and switch them to something that helps you.
Hope you got to enjoy the afternoon. I took S11 to get braces. Woo Hoo.
Me: 41 H: 42 Married: 13Y, together 24 Kids: S11, S9, D6 Bomb: 7/11/06, now piecing