There is nothing wrong with you. Not sure why you call it fear of commitment. You had one date. Talks about commitment aren’t even reasonable.

I think your guts just telling you that this guy isn’t right for you. Trust your guts. Personally I’d not date a cheater, so I don’t believe your thoughts are irrational. And even if he is a good guy, it’s been only one date. Commitment phobia after one date? You don’t even know him, why would you even want a commitment