Oddly enough, she's the one that's making herself unobtainable, now. And I feel like she's hiding her own feelings behind a serious facade. I'll be honest, I feel like Yamato inadvertently was bringing out the real Suzuka, up until his confession. Not that it was necessarily a mistake, but she was certainly seeming a lot more natural, more genuine around him. And now she's struggling with what he reminds her about.
At first, I was thinking she was basically just saying it was too soon- like she needed more time to sort her own feelings out... and maybe that's part of it, but there's actual baggage behind those feelings, too, it seems.