Did I just screw this up? (wall of text, includes tl;dr)

I'm a 23 year old guy. Not a ton of dating experience. I was in a relationship that ended a few months ago, but even with that one we didn't go out on many dates; we mostly just hung out at each other's places.

I can definitely be a bit shy and awkward at first, but I don't think I am too bad. I started looking at a dating site recently. When on a few dates here and there but wasn't really feeling it.

About 2 weeks ago I message one girl and she messages me back. We get to talking and seem to hit it off. She seems really sweet and funny, plus she's really cute. She actually gives me her number without me even asking (awesome), so the chatting continues via text. She drops some hints that she wants to hang out, so I ask her out and she accepts.

The night arrives, I pick her up, and we get something to eat. I am a little quiet as I normally am, but she doesn't seem to mind. She can't stay out too late, unfortunately, because she has a workshop thing that night for a scholarship. We walk around for a little bit, walk around a bookstore, talk more. As I said, I am pretty inexperienced with dating, so I suck at knowing when to make a move to hold her hand and stuff like that... so I don't try, lol. Anyway, she has to get back, so I drive her back to her place. When we get there, we begin our goodbyes, and I lean in and kiss her. All goes well, she smiles, says she'll see me again when she gets back from Thanksgiving break (she's in college). I drive home, have a text waiting for me from her again saying she had a good time. Mission success.

She leaves the next day for home. We text a little, one or two little conversations throughout the day. I know she's pretty busy with family so I don't want to bother her too much, nor do I want to seem pushy.

On Saturday, I text her in the morning. No response all day. Oh well, probably busy. Sunday, same thing. I text her at the end of the day, just asking if everything is okay. Still nothing for a few hours. She's flying back to school that night, so again I assume she is just busy. Text her once more and ask her to text me whenever she gets back in town if she can.

Monday, still nothin'. I'm a little hurt, because I thought we had a good time (I know I did). That night, I send her a message on the dating site, saying basically: "Wish you would respond, if you don't want to talk any more you can just tell me. I would like to get to know you better. I think you are really sweet and pretty. I think I can make you happy, so I hope I can get a chance to take you out again."

Next morning I see I have a new message from her. She says she has been sending texts, but I haven't been responding, so she thought I was no longer interested. I am pretty happy to hear that, so I text her back saying I never got them, must be a cell phone problem, and being the geek I am, start trying to trouble shoot it.

Seems like a happy ending. But now she doesn't seem to be responding to my messages on the site. Maybe my message came across the wrong way, maybe too strong? Should I try giving her a call, or would this only make it worse?

TL;DR: Met a girl online, went on a short date. She is really sweet, seems into me, even though I am a little shy/quiet. Kiss her at the end of the night, all seems to go well. She goes home for Thanksgiving break, we text a little each day, then she stops responding. I send her a message after a few days on the dating site, asking for a second chance. She responds saying she sent texts, but I never received them, still seems interested. Now it seems like she stopped replying to the online messages. I'm worried I came across too strong or something in my message, and am now contemplating calling her, but I worry this will make it worse.