I'm a lot older than your daughter, but also had a childhood marred by my mother's "moods' (I strongly suspect undiagnosed MH issues / depression but she never sought medical help). I have at various times in my life gone very LC, NC once for a period of about 6 months. Even now, although we 'get on' and I'm sure she would describe us to her friends as close, I keep her very much at arms length in terms of what she really, truly, knows about me as a person. Without being rude OP, you're not showing much emotional intelligence here - this isn't about you, it's about your daughter and what she needs, which is NC from you.
Your daughter is just becoming an adult - she's perhaps examining her relationship with you from an adult perspective for the first time, seeing your actions through the lens of someone who now could potentially become a mother herself before too long. And she's found you wanting, she wonders how you could have acted like that, done X, Y or Z when it's something she can't fathom doing herself in your shoes. She's so young, and she needs time to process it, to be angry with you, to be self destructive, to not give a fuck about your feelings, and to work out what her future relationship with you might look like, if she wants a relationship at all. And she needs to do that away from you - please leave her be. You say you didn't do anything awful - she's the one that gets to decide that, not you. My mother even now says things like 'oh I know I was a bit moody at times' or 'I did make a few mistakes' but those sentences in no way reflect how miserable, unloved, and unliked I felt as a child, and how that has affected me as an adult. She refuses to acknowledge any more than that, and on the rare occasions I've tried to discuss it with her just cries and says I'm being mean to an old lady, I don't understand etc etc.
My guess is at some point, when she's worked some of this through she will be in touch - but if / when she does, if she wants to talk about it my strong advice to you is to listen, listen properly to her truth, and be willing to be honest about your failings and what you could have done better. Don't make excuses. Listen to her and accept how she feels, and apologise sincerely. And be willing to take what she offers you, not demand more than she has to give. I wish you luck.