Casual Hookup Gone Awry

I've been dating casually for about six months now, meeting people through apps and going on first dates with them. Nothing has turned into anything serious yet, which is okay by me; I don't need to rush into a relationship right now. But I did meet someone recently who seemed very compatible, especially when it came to our shared interests in the bedroom. We met for coffee one afternoon and hit it off, going out on a dinner date later that week. We ended up at my place after dinner because we both had chemistry that was hard to ignore. Things progressed quickly, there was plenty of alcohol involved, which led us upstairs without too many words spoken between us. It felt right in the moment, and I enjoyed myself immensely throughout the night. But then came morning and reality: he seemed distant, almost cold, after things cooled down. He didn't return any calls or texts for a week until finally sending me an apologetic message saying that it had been more than he could handle emotionally. It wasn't something we needed to talk about now, he said. At first, I brushed off his sudden change of heart as typical after-sex blues and moved on. But then another guy did the same thing a month later, no explanation beyond vague references to how intense things had been for him, and it made me start questioning myself again. Was there something wrong with what we were doing that night? Did I push too hard or make some kind of unspoken assumption about where things would go? I haven't dated anyone new since, stuck in this loop of second-guessing my own desires and choices.