2 Year old Waking Up Every Hour

Our LO will be 2 in July. The past month, he went from sleeping 11/22 hours straight through the night to waking up every hour on the hour. He goes to bed at 7:00pm and puts himself to sleep easily. He sleeps soundly until midnight. Then he will wake up crying and screaming legit every hour until he gets up at 6/7am.

I’m not sure what to do but I’m at my wits end. I’m exhausted and expecting another baby July 1st and hoping to get him back to sleeping well before baby comes.

Any advice? Has this happened to you?

Thanks