Hi nenee! Keep in mind at this age they don't really have true fears of things like the dark or wardrobes, etc. It is just possible he is startling from you coming in the room, however.
Just to share my personal story, our dd was waking every 2.5-3hrs at night and we had her in our room. She was such a noisy sleeper that we decided to move her to her own room at 5weeks. The first night we did that she slept 5hrs twice in a row...so it turned out I was misinterpreting all her sleeping noises at night and thinking she was waking and hungry, it turned out she was just being noisy.
But yes, some babies are hungry every few hours at this age even at night. If he is truly hungry, you need to go ahead and feed him.
HTH!