If you feel like something is missing, it is probably because it is so. In order for a person to feel fulfilled, they need to have meaning both internally and externally.

Internal satisfaction with your life comes when you are pursuing your true calling. Everybody has dreams and vocations, even if sometimes it is a bit hard to discover them. When you turn them into a goal and actively work on achieving them, you charge yourself with meaning. No one feels unhappy or empty while proactively chasing their big passions.

The second part of the equation is something truly valuable in the external world. Even the most accomplished life feels empty if it is not shared with and/or dedicated to someone/something in the outer world. There is no fulfillment without love. So discover something that fills your heart and you will have found the missing part in your life.