Where to find happiness?

I’m feeling down and tired now, I want to be genuinely happy, but I don’t know how to do it or where to find happiness in this world.
I have a job, a decent family, and friends, but there’s a lack in my life. Every time I sleep, I always think about my future and what is missing in life for me to be happy. I smile and enjoy life, but when I am alone, I overthink to the point that it affects me. I don’t know what is happening to me.
I hope someone will enlighten me about what is going on with me. :smiling_face_with_tear: :face_holding_back_tears: