I had no idea how to word the title differently, sorry. It's a DAE + asking for advice

So, my FP (boyfriend) likes a certain fictional character. Nothing too extreme, he just think she's cool and it's his all time favorite character. I half-unconciously tried to be just like this certain character, I search a looot about her and kinda picked up some habits of her because of watching the show. This has been going on for YEARS.
I really don't like doing this, I feel obssessed and creepy. I really want to tell him this, but again, I think he'll inevitably find that a little weird, even if he says he won't.
I really hope someone out there can relate to this, I tried to find people with similar experiences in BPD/Maladaptive Daydreaming forums and had no luck so far. I feel really alone in this.