12 week old problems sleeping

[Lorna3012]

Up until a week ago my DS would sleep great at night. He is very unpredictable when he is tired and would cry before falling asleep but he'd normally sleep from 8.30 til 3ish, wake for a feed and then go down til about 7.30.

However for the last few days when we try to put him down he just cannot fall asleep. You can see he's dead tired, but even when we rock him, he falls asleep for 5 mins and then wakes right back up again. It took us 1h45m to get him to sleep last night and then his wake time is earlier, now 2ish. He's so restless when he sleeps, constantly tossing and turning and thrashing his head from side to side.

During the day he now refuses to nap, even if I persist with the semi morning routine we had.

Any insights?? It's completely thrown me off course and I'm lost. Could this be sleep regression coming early?

Sorry for the essay!!