Fussing isn't a bad thing, don't feel bad about it. You were only an hour late with a scheduled feeding and you don't KNOW that he was fussing for all that time or even fussing at all. I know you probably need to be more rigid than most with feedings since he was a preemie, but give yourself a break. There's no need to make it up to him, he is absolutely fine.
Newborn crying is pretty quiet - don't worry, they get louder, LOL! But how about using a monitor to help you hear him? Even if he's in the same room, a monitor would make his fussing louder and should wake at least one of you.