(Ace?) Lesbian crush on my straight friend?

As much as I fear opening up like this on a public forum, I need help. I don't have any queer friends to talk to, and I cannot bring myself to "come out" to straight friends before I have figured out my feelings with 100% certainty… This is very long (sorry!), so you can skip to the :help: at the end if you just want the bare bones of the issue!

Backstory: best friends for 5 years, long distance because I work abroad. Even so, we are best friends, text and skype daily and constantly tell each other how much we miss and love each other when we cannot talk for more than a few hours. We tell each other absolutely everything, from deep personal issues to what we had for breakfast, literally every day. She's the most important person in my life and I have never had such a connection with anyone. I want to hug her and make her happy and give her gifts and share icecream with her every day of my life, but the long distance part makes this impossible except for very short visits.

We both sort of identified as straight possibly asexual (no past boyfriends to base this on) but recently I've started considering myself bicurious, somewhat aesthetically attracted to female models and celebrities. My friend comments on the same female celebrities too, but "makes up for it" by talking about male actors much more often. We are both somewhat confused, but I've accepted that I may not be entirely straight while she keeps identifying as hetero.

I had honestly considered the idea of living our life as a happy, domestic asexual pair of best friends. My life goals revolved around saving up enough to move in together, and she always said she'd love to live together, too.

Then, she suddenly mentions a guy.
They're going out for a date.
My world crashed down on me.
I know it sounds stupid, but it's like the future I had imagined had been ripped away from me with the realization that she is, in fact, on the market for a boyfriend.

My feelings:
At that point I was forced to acknowledge that my extremely deep attachment to her must be vaguely romantic, if I can't stand the thought of her dating anyone else. I've always been terribly jealous and possessive when it comes to her, but I assumed it was a bff thing. So I came to the realization that I would happily date her myself, if I could. I am not physically attracted to her, but then again i am not physically attracted to anyone, have never been. (Except this one dude when I was 14?) I would however kiss and cuddle her, for sure. I do crave that kind of tactile connection.

I haven't been able to tell her anything about my most recent realizations, because she is a very insecure and anxious person who would probably cut all ties with me to save us both some suffering - and I can't imagine living without her friendship. At the same time, the idea of her being in love with someone else makes me cry b***h tears nearly every day. What she currently believes is: I'm very lonely and I don't want her to have a love life, because I wanted us to be "heterosexual life partners" as she put it. No romantic feelings. She says she would probably be happy living the rest of her life with me, but she still wants a husband and some kids, though she isn't sure whether she is asexual or not. Living with me would mean renouncing romance, to her.

As gnarly as it is, I guess she sees me as her best friend while I see her as my ideal life partner (platonically or not, I actually don't care) and it hurts like hell.

I don't know if I should tell her anything. I can't shake the hope that if I told her, she might eventually realize what we could have, living together, going on dates, having an idillic domestic life, adopting pets or even kids - I know I must have it bad if I'm thinking such crazy things when neither of us has even had a real relationship yet, but I can't help it. It's like my world has narrowed down to: I just want to be with her. But she doesn't want to be with me, not in the same way, or not exclusively.

I've thought about writing her a letter, just stating that while I am her best friend, I also would be open to something more… but then there's the ghastly fear that she'd just reply that she doesn't like girls, except for those two or three female celebrities that make her hot. And the ruined friendship would surely hurt more than the rejection.

:help: To sum it up: Never been attracted to girls, but I think I developed really strong romantic feelings for my long-distance possibly-ace probably-straight best friend. I'd date her in a heartbeat, but she doesn't know and she would probably be scared or uncomfortable if she did. She's never dated, but she labels herself as straight. She might start seeing a guy soon, and the very idea sends me into awful spirals of depression. Should I speak up? How should I do that? What should I say? I cannot bear to lose her friendship, but I can't stop thinking about how happy we could be together. I need some resolution, I can't keep pining like this. :help:

 

Thank you for your input! I'll try to figure out what I want to say in this letter, I'm just afraid of coming on too strong or make her uncomfortable.

 

Hey everyone. It's been a while and I still haven't been able to send her this letter.

My friend keeps saying she would marry me if only either of us were a man, which only breaks my heart every time. She says sex is the least important part of a relationship, but still says she is attracted exclusively to men. I feel like it's pointless to even tell her about my feelings, considering this.

I could use your help really confused and depressed.

 

Thank you for your reply!
I definitely still hope she may change her mind, if just because she's young and has never dated or experimented before.
I also hope she'd be enough of a good friend to keep being my friend even if I told her these things… But I can't be certain.

Still, keeping quiet is causing me to be moody and passive aggressive whenever she mentions a guy, and I don't want to be. I guess I do need some resolution one way or another. It may suck to be rejected, but i'm already crying myself to sleep as it is.