Thought I was straight, but I have feelings for my gender fluid friend?

So a friend of mine just came out to me as gender fluid. I was crazy into them last year when I didn't know they were gender fluid, and we used to flirt and text and it seemed likely we would start dating, but nothing came of that and they ended up dating one of my closest friends for around 8 months.
I didn't talk much to either of them during that time, and when my friend came out to me was really the first time we'd talked in about 5 months. Then we talked a lot that weekend, and they're in my 2nd semester health class so we've been talking a bit during that. They shared their tumblr account with me when they came out, because that's where they really express themself.
Anyway, they used to be male. But they tell me that almost 95% of the time they're actually female rather than male or nonbinary. I'm female, and I thought I was straight. But the pictures they put on their tumblr of them with make-up on and in dresses and all that, they take my breath away.
I think because there was no closure with our relationship in the past, I never entirely lost my feelings for them. And talking with and seeing them so often again just drudged everything back up. So I'm wondering whether I only like them because, well, it's THEM, or if I might actually be attracted to women? And is this just a fleeting feeling? Am I just caught up in the excitement?
They say they're more inclined to like women even though they're polysexual, so I have this crazy idea that there's a chance we could be together. But if they didn't want me before, why should I believe they'd want me now!?

So I guess if I boiled everything down, these are my biggest concerns: Are my feelings for them valid? And should I pursue a relationship with them?
I'll be honest since mid-sophomore year (it's late in Jr year now) I've been contemplating whether or not I was bisexual. I knew I could be romantically attracted to a girl, but I never wanted to believe I was sexually attracted to one. There have been two girls I've felt physical attraction toward though, if I'm being honest with myself. And I've certainly been struck by women I've met in shops and such before. Only I'm reluctant to admit to myself that I might be bi until I actually have a relationship with a girl. I love the LGBTQIA community, so I've always felt like I was forcing myself to be queer, which made me try my hardest to stay straight. So now with this crazy rejuvenated attraction towards this person, despite their being gender fluid, I want to think that I am bi! But what if I'm not!? What if the only reason I'm still into this person is because deep down I still see them as a guy? That's why I'm not sure my feelings for them are valid. And being that they're gender fluid, would my being attracted to them make me also polysexual or pansexual?
As per a relationship being plausible, I'm somewhere like the 30th person they came out to. So it's not as if I'm that special to them. And yeah they're into girls, but there are plenty of girls out there who are leagues better than I am. I also feel so unsure about everything concerning my feelings here, that I'm making no direct attempt to flirt. And as I mentioned, we nearly dated last year, I'm afraid they'll just never want to date me. To make things worse I'm afraid they'll have the same concerns as I do about my intentions, that they'll think I'm just running on old feelings and that I'm not actually attracted to them because I'm supposedly straight!

I'm sorry this is so long. I'm just the most insecure and unsure person ever, and this has been weighing on me. I'd like either to drop it and call it just an infatuation, or fully commit. Do you think I'm straight? Do you think I should try to have a relationship with this person? Thank you so much for your time and advice if you do end up answering me and my crazy questions. :icon_sad:

 

I actually did take the Kinsey scale test once! I scored a 2: Predominantly heterosexual, but more than incidentally homosexual. Which is making sense now "^_^ I've just never thought realistically about possibly being queer (my mom is sort of a homophobe, which may have contributed to that and to my utter confusion at the moment). As of now my friend doesn't seem to want to transition, they would like to take female hormones, but are against GRS. And actually the girl they dated broke up with them after they came out to her, so she didn't know going into things. Thank you for your advice, I really appreciate it. I'm not going to rush into anything I suppose, though maybe I will talk to them about this, somewhat. I'll definitely stop beating myself up for being attracted to them though, if it's bothering me this much then the feelings must be genuine. Again thank you, have a nice day!