My son will be 5 months on Saturday, but for the last two nights he's been up until 12/1 after putting him to bed at 8pm. We feed him and then rock him until he's sleeping or almost asleep. We put him in his crib and he's happily asleep within 10 minutes. However, he only stays asleep for 1 - 1 1/2 hours before he's awake and screaming.

Most of the time he'd sleep from 7/8pm to 1/2am and then until 6am. Only a few times would he wake up after a couple hours.

Up until now, I'd let him cry for 10 minutes, then go in and put my hand on his chest or face and he'd fall back asleep. Never picked him up.

But these last couple nights, that doesn't comfort him. He doesn't stop crying unless I pick him up. I'll rock him back to sleep or nurse him. But as soon as I put him down, he's screaming again. This goes on until midnight. Then he'll sleep until 4/5am.

I've tried giving him gas drops, but that doesn't seem to be the issue.

He's perfectly happy and well-rested when we have to get up for the day at 6/7am, but I, on the other hand, am miserable.

Is this the sleep regression I've been dreading or something else?