You definitely shouldn't trick yourself into happiness, but the attitude you set for yourself in whatever it is you are doing often determines how you will feel about what it is you are doing or did, later on. Don't attempt to trick yourself though that will spiral into worse feelings when you start questioning it. You don't need to trick yourself anon, you need to have a good attitude about the things you are doing. When you have a good attitude the people around you will notice, you can deal with a lot more shit, and that overtime will lead to you have a better day.
God bless ya