I've (habitually) always considered my self straight until now

I'm a 21 year old female. I've have always considered myself straight, although I can distinctly remember in high school questioning whether or not bisexual might be a "thing" for me. I've never discounted the idea and I'm a firm believer that sexuality is fluid.

Now I'm beginning to wonder if I'm not actually bisexual.
It's only been within the past year and a half that I've grown into my sexuality in any sense. For a time line of sorts, I can remember about a year and a half ago having an erotic dream involving my roommate at the time-who has since come out as lesbian.
I lost my virginity, to a man, slightly over a year ago.
I can only remember the three dreams I'm writing about now in terms of erotic dreams.
Within the past year, I remember one dream where I was with a man but where the details all seemed to be fuzzy. Then, I had a dream that I was sleeping with a male coworker of mine, and in the dream, closed my eyes and upon reopening them, my male coworker has morphed and I suddenly realized I was actually engaging with one of my female coworkers.

I've also had a threesome that included myself, my boyfriend at the time, and a mutual friend that is openly bisexual. There was alcohol involved but I typically have a fairly good grasp on whether or not the decision I may make is wrong...
Initially I was opposed--mostly bc this other girl not only has a reputation for being kind of manic, but she had also just broken up with a guy that I had to work with 5 days a week.
I won't deny though that, even though I've only slept with men since, I enjoyed myself that night and she got me much much closer to orgasm than any man ever had.

Like I said, I've only been with men since, and I feel like the large majority of the time, I notice men.
FAST FORWARD
to my current situation.
About a month ago, I met this girl that works at the bar a few doors down from the cafe I work in. The first day I met her, I knew I wanted to get to know her, at least in the friendly sense. But we only talked about 10 min that day.a few days later, she came in the cafe where I work and about ten minutes after she left, a light bulb suddenly went off in my head that 1. I was physically attracted to her 2. I'd handled the conversation/transaction the exact same way I would have if it had been a cute guy on the other side of the counter 3. I was not only physically attracted to her but I always seriously wanted to get to know her.

Within the past week or so, I have opened up to a few mutual friends about my crush on her --all of whom now I have a tendency to be a scaredy cat because of my ability to WAY over analyze and over think things. This in mind, I think one of them (who has a second job working at the bar where my crush works) thought they were only helping the situation by telling this girl I liked her. M
Granted, I'm kind of glad she knows. But I feel like I lost a big chunk of time that I was using to sort this all out in my head, and now I find myself distancing myself a bit because, frankly, I think a) I'm kind of terrified and b) I don't know if she is now expecting me to make a move and c) I'm scared in a way of getting too close to her bc given that I consider myself to be "questioning" now, the overanalytical part of me is afraid I'd "change my mind" and end up hurting her.
She and I have been kind of inseparable for quite a few days but I feel myself emotionally pulling back (something I do often; I don't let people get close to me usually)

In one of my many, very long talks with her, I very briefly and in an undefined manner addressed my sexuality. ("I've never labeled myself bisexual but I've never discounted it/ I've been with a women but mostly men"/(without ever directly saying I was talking about her) "I think one of my biggest harbors fears is meeting a woman and having her think that she is my "college experiment"
Basiclly I would never want to hurt this girl, I was trying to let her know that I'm afraid my questioning-state-of-being could possibly one day hurt her.
I don't want to distance myself from her, but it is second nature for me to do that to anyone I start to get close with in order to avoid pain.
I'm not sure what else to add...
But I'm mostly looking for advice/thoughts or any clarity you might be able to help me find.

 

I plan to, when the times right, be completely honest about it.
Honestly though I think I'm bisexual but hearing it from someone else makes it, I don't know, more real? I feel like without that, I just doubt myself into submissuon