And for me it was the time where I really internalized that life isn't about the goals, its about the trip and the stops along the way. Imagine your life is to drive from the San Francisco Airport to JFK in New York and catch a flight and fly back. That is your life. And sure you put goals in like "see the Grand Canyon" or something which takes you down a side path but once you have seen the Canyon, maybe hiked Zion, skiied the Rockies, you just have to keep driving east. And you hit Kansas which goes on and on and on and on and on.
I had started piling up things from the 'someday' pile into the 'remember when?' pile, like from 'someday I'll have kids' to 'remember when we didn't have kids?' When that 'someday' pile gets smaller you can imagine it has nothing in it but 'someday I'm going to die' well that is a scary thing to imagine indeed.
So it sucks, but what can you do about it? The thing I found that got me past that was focusing really hard on what I had (a great family), what I could change (where I wanted to be), and how I felt about the world (my outlook on the future). By focusing on that I kept from looking at that ugly visage of Christmas Yet to Come, and the fear and guilt that came along with it. I stopped following the news for a while since it only wanted to reinforce my fear of the future. I fed my curiosity and tried to seek out sources of wonder again (rocketry, quantum physics, and robotics systems are all amazing things to me).
That keeps me engaged and interested and learning, and in so doing keeps the future away in the future.