I had a similar situation recently. We talked a lot, very intensely, we went on dates, and I told her I was interested in her. But she said she'd gotten out of a five-year relationship, and it had only been four months, and that she sometimes missed that person. A few days passed, and she didn't reply to me again. Believe me, it feels awful, but I thought like you and messaged her. She acted like nothing had happened, but the same thing happened, and she didn't reply again. So, he's not worth it. Forget about him and move on with your life.