why do I like her?

Hi! Thank you right now because I was really looking for a forum like this!

I just been thinking about something and I need to know what's happening with me.
So, I'll try to be short but ask me anything if you want.

I've been in love with a friend of mine for a little over a year and it is becoming really hard for me because she has a boyfriend and things will never work between the two of us. Because I want to forget her and it's being really difficult, I'm starting to try to understand what's in her that I like so much. I've met way prettier and more interesting people than her, she is not a mistery for me anymore so why do I like her? And after reading some things on the internet I came across something that said that we look for the kind of love we were raised in. Kind of like, we fall for people who remind us how our parents loved/love us. And I'm starting to think it must be it.
Sometimes she does things that I think "that's so like my mother" and she treats me really well and is super nice and when i think about it, I first started having feelings for her after a night out when i got drunk and she kind of took care of me. My mother gives me a LOT of love so maybe I'm looking for some love like that. BUT WHY?? I don't know if i want that. I don't know if its normal to feel the need of being taken care of. What's happening with me?
Any help is appreciated

(also, just for reference, yeah I'm a girl, probably bissexual, but this is not the first time, teachers, older women, etc.. I see a pattern, I just don't know what it means and if it's normal)