Where's my little angel gone?

I was going to post something on here last night about my gorgeous little man. He has been like a child possessed the last few days. I don't know whether it just because O's on holidays and our routine is all out of whack. Plus O's a bit of a push over and Jack has been pretty much getting everything he demands. Anyway we've had some shocking tantrums and some sleep issues which makes me so very cranky. Jack has never been a very good sleeper and has only slept right through the night less than 20 times and the kids nearly 2. The other morning though he woke up at 4ish and proceeded to scream hysterically for about 2 hours until we finally couldn't take it anymore and put him in the car and went for a drive. It took him about 40 minutes to fall asleep but then when we got home we all went back to bed and slept until 11 so at least that was a relief. I don't know if he's having nightmares or what but he has been near impossible to re-settle lately. Anyway, I'm sure it's just a phase or just because his routines out and everything will get back to normal soon. I hope anyway.