How to stop smothering girlfriend?

We met three weeks ago and I asked her out after the first week. I'm smothering her and I can't stop. I suffer from anxiety anyways, so its hard to calm down and take everything slow. We've been talking on facebook everyday and phone, and can't help myself. Yesterday she asked me, "do you know you ask sooooooo many questions =)". I said sorry and ya =P , I got off and haven't gotten back on facebook or talked to her again. I'm extremely nervous now, I feel like I ruined it with her. My plan is to not to talk to her for 3-4 days, even if she tries. Is this a good plan? What should I do? ps were both 19.