Why did she stop talking to me?

You shouldn't have texted her so fast when she told you to. If a girl tells me to text her, I'll usually wait a day or two before I even do. They don't get mad or anything if you don't bring up the time. She'll like it. And sending her another message after you already did makes you seem even more desperate. I used to do that and get the same thing but trust me don't. If you text her and she doesn't respond. Don't be the one to text her first for at least the next 2 times. Be layed back and don't show her you rely on her so much. She'll try to get your attention more that way. You're showing her that you're attracted to her too much and it's turning her off. Just take it easy. Don't initiate any conversation anymore. Let her be the one to start it. And act like your busy. If she texts you saying "What's up". Never ever ever say "Nothing, you?" always say you're doing something, even if your not. If you're just watching Tv tell her what show you're watching. Seem busy, and don't reply immeadiatly, respond in 4 or 5 minutes. She will start talking to you more. Just don't come on so strong. That doesn't mean don't ask her out again. But wait until she comes around again. Good Luck.