DS did have night terrors and confusional arousal. It lasted for almost a year. All you can do is be there for him and be patient. I could never leave to room until he was calm enough and ready for us to leave. I don't think our DS even remembered his episodes. They are very stressful but it doeas get easier when you can relax about it yourself. There's really nothing you can do other that softly talk to him and let him know your there. He alway had occasional terrors since he was about 10months old, maybe once every few months, but last summer we moved into a new house, had a baby, potty trained all within a few months. Thats when we started getting nightly wakings lasting anywhere between15min-1hr. It even came to a point where he had a few per night. I'm not saying this will happen to your LO though. Our DS hasen't had one in over a month and it feels great, so it won't last for you either. You also have a baby, could it be the change is triggering this. Any changes at all can start NT and CA.
So be calm and huge hugs to you. It's no fun at all.