you should check closer to see if your child is awake. as a child i had a lot of night terrors... my son has also had a couple... where i would be sitting up screaming, whatever... and my eyes would even be open, but rolled back.. there was and still is NOTHING any parent can do about them to make them go away. the general advice to parents is to just stay with the child and make sure they arent in physical danger.... you can try to comfort them, mostly that makes me feel better. lol. they usually stop after no more than 5 minutes.
the only advice ive ever heard of is to time how long it takes between falling asleep and having this terror, and wake the child up about 10 minutes or 30 minutes before that... take them to the bathroom, get a drink of water, snuggle. thats the ONLY thing ive ever read that is supposed to at least help.
kids grow out of this, so dont panic that this will be something that lasts forever. www.askdrsears.com has information that could be helpful and you can get the sleep book and there is info in there that might help you.
he could also be having nightmares, especially on the times he is actually awake. you will be able to tell the difference, because he will respond to you when you come in the room, with a night terror he wont.
the times he wants to cuddle could be a nightmare or it could be that he woke himself up in the night terror and was scared then too...
the night terrors dont get remembered in the morning either, so dont worry about that.
its scary, and i hope that it gets better soon....