Hi, I tend to this a lot too.
Now keep in mind that I (nor you) have been officially diagnosed but I found the term Maladaptive Daydreaming to be most fitting for me.

I don't know too much about it myself as once I discovered what I was doing wasn't "normal" and I decided I rather not know too much. Don't do that, its unhealthy really.

What I have picked up is though that generally in these realities people usually make themselves a hero of some sort.

On top of that certain types of media such as music, TV, movies, stories, etc. heavily influence these realities and how you shape them.

I hope this is somewhat helpful to you. If its becoming a real problem please get help.

Good luck friend