My daughter had night terrors for several years, almost every night, some very short others lasting up to an hour, really quite upsetting. It was usually within an hour of first falling asleep. Like you, we had to just be around to soothe and watch our for her. I found that gently holding her had seemed to calm her and also, when she yawned, that seemd to be the end of it... I used to wait for those yawns! Any more interaction than holding her hand made matters worse for her. Earlier bedtimes helped and she also had fewer when her little sister moved in to share the room with her. She's eight now and they are, gladly, now a rarity. All the best with your little boy, I hope he grows out of them fast.