I think we're similar, Ive always been heavily into my imaginary worlds, stories, etc. I cant imagine not being creative to the extent that I am and Ive found it hard to understand how people can not have characters/worlds, etc. my close friends have paracosms or close to as well.
for your qustion, I dont think they can really be distinguished. this kind of creativity is always in some way dissociative (daydreaming is natural dissociation) but that dosnt necessarily mean it's negative. depends how it's used I think.
I'm a system; I have a disociative disorder, my alters are irreversibly imbued into my worlds and stories because creativity has always been how I've coped. I think Ill always have a chickenVSegg debate for some of my worlds/alters. without this outlet I wouldnt have unknowingly created spaces for some of them to form connections to and support/help one another. Ive processed and explored a lot of things through my creativity and its helped me confront a lot of difficult ideas, which prepared me some for therapy. and it's also been such a intense source of harm because I am a self punishing person, and to reinforce the views that I had to keep me safe but were hurting me and keeping me stuck.
I guess like all stuff its about measure. I know someone who gets a lot of joy and passion from her worlds but when she's in a bad place has to be careful to not go and live in them like she did when she was younger.
I think youre a lot more escapist than me, if youre finding that difficult / making real life harder to deal with maybe that's something to look at. I dont think it's bad at all to have comforting/better places creatively and in your mind, it is a good coping mechanism, and creativity can be very motivating in my experience, but if theyre reinforcing your experience/views of the outside world, maybe that is regressive in some way? which isnt to say it has to be got rid of but maybe adapted and adjusted?
I dont really know how to explain/express this idea because it's not a skill Ive consciously built so I dont have the words for it, but are you using this to abandon reality as hopeless, or to compliment and cope with/remedy it?