Most people have the habit to review their achievements and failures at the end of the year. There are many people who are happy even with the small incidents that happened while there are others who are never satisfied. Life is unpredictable and not everything happens as we wish.
So, instead of getting sad, you should celebrate your achievements like you have a roof on your head, a family that loves you the most and is always there for you in your bad time, friends who are always there to cheer you up and the time you spent with them. Be grateful to the going year and welcome the New Year to hold on to new opportunities.