Sebstar, the minute you're born, the countdown starts, time starts running out and we are all going down, no exceptions! Someone once said, '....we shouldn't fear death... because death is as natural as being born'.
So, instead of counting down the days as one 'less', start counting them up as one 'more' ......one more day on this Earth to celebrate the sunshine, to hear a loved one's voice on the phone, to see your grandchildren perform in their school play; in short, one more opportunity to celebrate all the things that are good in life and to dwell on finding happiness even in the most simple things.
Every day you wake up in the morning, should be another notch in your 'count up'. Start savoring all the happy moments as you live them and add them up each day. Before you go to bed at night, make a mental list of your three happiest moments that day.
Speculating about a future event whose timing is unknown is an exercise in futility. Why so much doom and gloom? Between now and then, there could be many good things in store for you too....why not dwell on that?