Is it normal to daydream about a character as though they're my significant other?

Not in an anime waifu sort of way, I'm a guy with ADHD and I'm hyperfixated on a character/persona of the lead singer of a band I'm into.

I go through my days thinking to myself as though he's there with me- talking to him in my head, picturing his reactions to things, etc. I also have an idealized version of myself I imagine in his universe, taking place kind of concurrently like a multiverse scenario. It's still me, I just sort of 'tune in' to that version of me and can still operate in this universe as well while daydreaming about being alternate-me.

This isn't a personal detriment, it doesn't cause any strife as I never act outwardly in any way like that's the case- for all intents and purposes I come off as a completely normal person.

It makes me happy and comfortable to imagine him with me, and to some degree feels like a real relationship. I've done this with several different characters in the past- at this point I'm thinking its something to do with my ADHD and some kind of poor grasp on fiction vs. reality & my hyperfixations.

What also worries me is that I have a real boyfriend as well. I adore him, he makes me so happy and I'm very lucky. We're long distance, but talk often. We've been together for almost two years. I never ignore him to spend time with the man in my mind, but it's easy to imagine the character with me more often since it's an idealized fantasy where there's no repercussions and everything is fluffy and nice all the time.

I've never told anyone that I do this. People know I hyperfixate, but I've never discussed the daydream world(s) in my mind that are just constantly running almost 24/7. Is this normal, or at least not batshit insane?

(woof, sorry for the essay. got a little impasssioned, i guess.)