My son is nearly 5 months old. He's always been a fairly good sleeper. Always woken up for 2-3 feeds but straight back to sleep after. All of a sudden his sleep has completely changed. He sleeps for an hour at a time then wakes up to chat, wakes up for 2-3 hours at a time in the middle of the night, just chatting and screaming (because he finds it funny not because he's upset). I'm utterly shattered, and exasperated by it! Is this normal? Does it get better. I'm so, so tired...