Maladaptive Daydreaming: where wild minds come to rest
Why not join an amateur dramatics group? If you role-play the chances are you have the makings of an actor. I am quite a good mimic and can do all kinds of accents, which I attribute to my MDD.
You can definitely create story lines with this and maybe write something... I've never used it to my advantage but sometimes I feel like I could make a movie about something or even act in one because of my facial expressions and the way I talk/act as different personas. Personally, I'm always me, but a different kind of me.. but some people make up different people in their fantasies.. it all depends on how you daydream.
Karen Pimentel is on point about using your daydreams for writing ideas. I have begun using my extensive daydreams to write short science fiction and fantasy stories and I am hoping to get enough practice with it to get something published. If writing isn't your thing, try painting or photoshopping a scene from a daydream. If you use it right, MD can be a huge advantage for the amateur to professional artist. Good luck!
Ps- https://www.reddit.com/r/WritingPrompts/ Can give you a good place to start a daydream that could turn into a cool story.
Mostly, people go with MDD, since it always seems the best way to channel your dreams. But since you say you roleplay, I'll go with Michael and suggest you go for acting- or anything that involves any form of creativity and something you're good at. Just play to your strengths!
Writing and drawing are 2 things I wouldn't be able to do without MD. In fact if I didn't had it I wouldn't be able to do it since I'm by nature a very bad writer and I never learned anything about drawing.
I both write and draw things from my imagination and for me it can give me some nice results whene other work isn't too much ;)