In your guy's case, the wheels started to wobble with the first text and flew off completely with the second one, causing him to crash and burn. Then the poor dumb bastard kept texting you even though he was on fire and dying.
Here's what a normal guy (like me) would do. If I went out with someone and liked her, I would call and leave her a message. Then I would give her a couple of days to answer before I contacted her again--not the very next day, and NOT a text. A phone call, like, two or three days later. Then I would give her another day or two to answer. If she didn't reply by then, I would go over to her house and stand outside her window in the rain wearing a trench coat and holding a boom box over my head that was playing a song she liked. Okay, that's a lie. If she didn't reply after two messages, I would assume she wasn't interested and move on. I would save the boom box move for someone I liked more.
Your guy was already throwing out red flags with the first text. For one, he didn't even give you a day to reply. Second, did you tell him he could text you? I think it's rude to text someone unless they have encouraged you to do so, because a text is more of an interruption than an e-mail or, in some cases, even a phone call. Then he gave you the old "Was it something I said?" line, which is a pathetic thing to ask someone you dated one time and called just the night before. He knows he did nothing wrong; it's a tactic to get you to call back sooner.
You call him creepy, I call him desperate and insecure and socially inept. Whatever you call it, do you want to date it? At best he's a strong type-A personality who wants what he wants when he wants it; at worst he's a sad insecure man who starts to worry if you don't call him back within the hour. Can you tolerate either of those in a boyfriend?
Thanks for the question.