Am I coming on too strong.

There is a girl that I have been texting for over a month. We meet each other on a online dating site, and talked every night to get to know one another. She'd say things like that she enjoyed talking to me, and that talking to me was different, but a good kind of different. She snapped chat a lot too. We finally met each other Sunday. We did something simple to break the ice. We walked down a nature trail to a water fall and walked back. After our little meet up, she said I was a really nice and mature. We made plans to meet again a week later.
Now here is where I'm having the issue. I would text her good morning a lot, and would tell her have a nice day and that we would talk later. (Please note, she did the same thing too a lot before our first meet up as well.) After I would be done work, I would text her and asked if she had a good day. And we'd chat until it was time to go to sleep. But for the last few days when repeating this process, she would take longer to reply to texts, and also hasn't really snapped chat either. And she would also put a lot of emojis into her texts which she hasn't done either. She also canceled our date for Sunday. I asked if Wednesday would work and she said she'll have to wait and see. I talked to one expert who said I may be talking to her too much and I'm causing her to lose interest. Which I find odd because she said she enjoyed talking to me every night. So I have laid off the texting a lot, and now only wait her her to text and take my time replying to her texts, but I feel I might be doing something wrong. I have little to no experience with dating or with girls, so thoughts and advice would be appreciated.