The fact that you're conflating being bisexual with being confused is honestly classic biphobia.
Your OP very much has an undertone that you would rather your daughter wasn't bisexual.
"Gay, straight or whatever" is also hugely dismissive- my sexuality isn't "whatever".
I don't think you're biphobic in the sense that you'd actively abuse someone for being bisexual, but I think you have internalised a lot of the biphobic messages that society presents us with. And I think it would be really worth being honest with yourself about this- regardless of whether your daughter is bisexual or not.
@SansaSnark I don't get this vibe from the OP's posts at all. I'm bi myself so very aware of biphobia, but 'gay, straight or whatever' is an accepting message imho. Just because she didn't say LGBTQI+ doesn't mean she's being dismissive. I read the 'whatever' to encompass all of the various possibilities.
I wish to goodness my parents had told me they'd still love me if I was 'gay, straight or whatever' - they were very judgemental and invalidating when I realised I was bi as a teen, and more or less tried to 'forbid' me to explore my sexuality. (I was about 18 at the time, so they couldn't exactly stop me!) I never managed to get to the bottom of the prejudice or where it came from, but the lack of acceptance really hurt at the time and I often wonder how I would have been treated if I'd chosen to marry a woman rather than a man.
OP personally I'd avoid the word 'confused' in talking about this with your daughter as she could find it invalidating, but otherwise I think you're already doing the right things to support her. You told her she will always be loved unconditionally and that's what matters.