Is there a word for feeling nostalgia for something while you're still going through it?

When I was a kid, my parents got together with several neighborhood couples every New Year's Eve, switching houses each year so each couple hosted once every few years. On December 31st, 1960, when I was seven years old, the party was at our house. I mingled with the guests for a while but when I eventually went up to my room around 10 PM I was overwhelmed with sadness for the passing of the year. I couldn't believe it was about to end and would never be here again and I wanted to hold on to it, desperately. I decided I would try to capture the year and I actually got a jar from the kitchen, filled it with "1960 air", and closed the lid tightly. Somehow I remember rationally understanding that as soon as the clock struck midnight that air would immediately become "1961 air", but some irrational part of me thought it was a way of preserving the past. If I opened it I could at least take one more breath of 1960 air! It was confusing and disorienting and when I mentioned it to my mother the next day she was bemused; I think she thought it charming but silly. But I remember it to this day, vividly.