I (20M) asked a girl out (20F) who initially said yes but then emotionally shut down the next week

At work I (20M) built up a pretty solid connection with a girl (20F) over the last few months. She is more on the introverted/shy side but eventually warmed up to me and we had a different dynamic than what she had with the rest of the people at work. I needed up asking her out in a pretty low pressure/open ended way by asking if she’d be down to do something one of these days after work. She initially seemed happy and onboard and said we should. So it seemed the deal was done and that I would just have to eventually schedule something with her. This was on a Friday so I didn’t see her until Tuesday the following week. The next week she completely changed up on me, she barely spoke to me, gave short replies, couldn’t even look at me, etc… she was pretty much giving me the cold shoulder. I’m very confused because it seemed like everything was good and that she was on board when I asked. Did I do something wrong that made her change up like this? Should I try to talk to her about it should I just accept it?

TL;DR, I asked a girl out at work who I built up a solid connection with and she originally said yes and seemed happy about it but the next week at work she completely avoided interacting with me