How can this be happening?

Hi everyone! I'm new here, and I would very much appreciate any thoughts/advice anyone has on this:

For a short summary: I am 19 years old female, have always had only feelings for males, and recently came to the realization that I have developed strong romantic feelings for a close girl friend.

The long version: From when I was a child, I developed intense, all-consuming crushes on boys. I always found them physically attractive and would romanticize and daydream about them quite a lot. Due to shyness, I was almost never able to pursue a relationship with these crushes. As I entered high school I felt quite a strong longing to be in a relationship with a boy (not a specific one, just any boy). I continued my pattern of long-term crushes. Again I never pursued a relationship due to shyness and anxiety. My senior year I met a boy while swing-dancing, he asked for my number, and we ended up going on two dates. I remember feeling quite giddy while dancing with him, but while I was elated and 'fluttery' while getting to know him over text, I'm pretty sure those feelings were more about getting some romantic attention, finally. We were pretty completely incompatible and I did not see him any more after that.

This past year (a gap year) while I was on a study-abroad exchange I crushed heavily on one of my fellow students, a boy. Again, never pursued anything about it.
To be completely clear, I have never kissed or done anything physical with anyone. (I realize this is unusual at my age, lol)

This past winter, I began working at a new job. And at this job, I met a lovely, intelligent girl (my age). We bonded initially over love of a book series, and talked all during that shift. Due to mutual introversion and shyness, it took a couple months of only sharing a shift perhaps once a week to start developing a friendship outside of work. Our friendship grew gradually, propelled my a mutual love of books, musicals, and some other things. I was astonished by how much I had in common with this girl (as well as perhaps 'superficial' interests, we share some strong personality traits, and general views and values.) She had actually come out to me as bi during one of our first few talks during shifts at the job (we were discussing LGBT+ characters in a book, and were both saying how wonderful it was that they were so well-represented in this particular book). We began spending more and more time together, opening up more and more, until now we talk almost every day. I now count her as one of the best friends I have.
Simply put, I thought (and think) she was one of the coolest, most interesting, and most genuine and sensitive people I had ever met. And up until a week ago, I was convinced I harbored strictly platonic feelings for her.

However, after we said good-bye (after hanging out for hours), I became extremely upset. After trying to ignore these feelings, I eventually started talking to my dad (who is very supportive and understanding) about how I felt. During that conversation I found myself crying and struggling to confess that I may like this friend as something more. I realized that there were multiple things I had been brushing off for the past two months that probably meant I liked her romantically. (For example: thinking about her ALL the time, wanting to share all the little random interesting things I found throughout the day with her, getting a little jealous of her spending time with other people, caring very deeply about her happiness, liking the way she smelled, getting extremely upset about leaving her when I go to college this fall.) After quite a long talk with my dad, and then another one the next day (at first I was extremely confused and doubting myself), I finally admitted that I do have romantic feelings for this girl. (I allowed myself to daydream about going on a date, kissing, and cuddling with her and it made me very happy.)

This week I've been thinking a lot about how over the past year or so I've been struck more and more by beautiful women (mostly on tv shows/movies). And I also remembered being infatuated with a beautiful girl who was a couple years older than me when I was 12.

So I guess now what I'm wondering is, is it possible for this to have happened??! To think you are straight and then at 19 years of age develop feelings for someone of the same gender? Or I guess, more accurately, what does this mean? Would it be more likely that I am 'heteroflexible', or perhaps somewhere on the spectrum of bisexuality and have perhaps been repressing this (I am wondering more and more about this due to how much I denied my feelings for this girl for two months.)

And, I know this is probably something I'm just going to have to figure out, but would it really be fair of me to bring up these feelings to her when I'm leaving? Because most importantly I want to remain friends with this wonderful person.

I would very much appreciate any thoughts you have about all of this. I'm just one confused duckie.

 

Perhaps I should also add that up until I was about 14 I had never thought much about LGBT+ issues in general, and I was raised as a Christian. When I was 14 I briefly became much more involved in the church as a place to belong and (I am ashamed to say) briefly questioned whether being LGBT+ was 'wrong'. And clearly it is perfectly good and wonderful to be LGBT+! But just wanted to add that I didn't develop that attitude until I was 15-ish.

 

Thank you so much for your responses! I really appreciate your thoughts, and knowing that this has happened to someone other than me! It's just been rather disconcerting to find that a core aspect of my identity might be different than I thought. I find myself still thinking sometimes "No, this can't possibly be happening, I'm probably just confusing deep platonic attraction for something else." Which I know isn't true, but...what can ya do, minds are fickle things! And I'm also trying to tell myself that I don't need to figure out RIGHT NOW exactly what sexual identity would fit me best, but...not knowing for sure is hard.

 

Thanks for the advice, SkyWinter. I actually did end up confessing my feelings, simply because it was making me too nervous to continue without doing so. (She does not return my feelings, of which I was already pretty certain. However, we had a really good conversation and it seems like we will be able to continue our friendship, which is great. So now for the business of falling out of these feelings...sigh.) I was wondering if those of you who did realize your attraction to those of the same gender later would mind giving me some advice on exploring your newfound attractions? I guess, (well, part of me wants to ask, 'how can I be sure'?, but that's pretty impossible to answer) what I want to know is, what would be helpful during this time of uncertainty about my sexual identity?