Happiness comes from deep inside you. It’s a feeling that is almost a “skill” in that the more you practice making yourself happy, the easier it gets.
In the beginning you might have to work at looking around and seeing all the good that surrounds you, recognizing how very lucky you are to be enjoying another day, how wonderful it is to be surrounded by interesting people, how terrific it is to have more exciting things you want to do than you have the time or energy to do them, how special it is to have someone you love.
As with anything else, no practice is ever perfect. If you work at it every day, you’ll get better and better.