I can relate 100%. I'm in the middle of an in-house separation that's going on 6 months (3 months in separate bedrooms) and today was tough. I had many of the same thoughts about this being our last Christmas under the same roof etc.
My own thread is here, if it's of any interest to you or others -- I don't want to hijack yours, but it shows you where my perspective is coming from:
Don't beat yourself up for your failings. I failed at least 2x this Christmas, in terms of maintaining frame. I tried to give her a hug last night (Christmas Eve) after we'd finished wrapping up the gifts for the kids and were heading to our separate bedrooms around 1am -- she let me hug her but kept it "standoffish." Then tonight, after Christmas Day was over and the kids were in bed, she was heading up to her room for bed while I was in the living room and she said "Goodnight" and I said "Merry Christmas," she replied "Merry Christmas" ... then I stupidly said "I love you" as she turned her back and walked away. Ooosh.
My emotions were also all over the place today. I think it's to be expected with Christmas and children around. Stay strong, brother.
