Conversation fizzling out after a great first date.

So I 32m am seeing this girl 27f, we met on hinge and we're talking for a month before deciding to meet. She lives about two hours away and I decided to take the drive instead of meeting midway because I thought at least one of us should know the area. I spoke to her about renting a room so we didn't have to worry about me having to drive back the same day. She thought it was a good idea although told me she would avoid my room, and that was all totally fine. I told her I respected her boundaries and would never push her to come back; that it was purely so I could enjoy the day and not have to worry about driving.

I got there and we really really hit it off. We spent two hours just talking and before we realized it time had flew by. Instead of planning we kept it open and after brunch we bought a cooler and ice and a sixer and sushi then headed to the beach where we spent another couple of hours. We snuggled a bit and it was honestly the best first date I've ever had. I asked to kiss her and she said no, which confused me a bit because everything felt so right. But okay, it didn't even make things awkward we just kept on and even laughed it off. I felt so comfortable the entire time.

After the beach she drove me back to my car so I could check into my room. At this point I was prepared to say goodbye but to my delight, she wanted to do something else. We made plans to meet her friends at a local bar but would use the bathroom in my room first. After peeing I come out to find her laying on the bed and, as you can guess, one thing led to another and we never made it to the bar. Most if not all of the intimacy was by her initiation, which I feel is relevant to this story because of my rejection on the beach. She didn't spend the night but we met up for breakfast the morning after and she was visibly sad to see me go. I asked her if she had a good time, and if she wanted to see each other again, and she said she did. (Later on via phonecall, I brought this up to her again and she responded with "we can hangout if you want, sure.") So now to the frustrating part...

Get home, and texting is noticably different. Like no cute stuff, no sexy talk, short answers. Basically I'm sensing little or no desire to engage in conversation when before we met it was all the opposite. Last night she called out of the blue and we had a great talk like before. Then today we barely talked at all. I'm trying not to overthink this but I can't help but be slightly frustrated. If we both had a great time, what would be the reason for the change in communication? Are we moving to fast or is she just not into me and doesn't know how to be honest about her feelings? I'm upset because all my indicators were flashing success and compatibility and now I don't know what to think. Should I talk to her about it or just give her some space?

Tl;Dr - Had an amazing first date, total click, so comfortable. Thought she felt the same way but sensed a change in communication afterwards.

Edit: To be clear it's been one week since our date and things have been gradually petering out.