Came to say exactly this. Lost my dad at 18 and I'm 37 now, you just learn to live with it. Time makes it easier because it distances you and gives you lots of other experiences without them, but even decades later you might catch yourself thinking about them.

I always remember a quote by (GNU) Terry Pratchett:

No one is actually dead until the ripples they cause in the world die away

And you yourself are a ripple, your father is alive within you, remember him and carry him with you.