Help! Night waking with 11 month old

I seriously need help. Maybe this is obvious but I'm a FTM that is super tired so please help a girl out if you can.

My 11 month old just started doing this thing where he gets up around 1pm or so and nurses for an hour and then screams and beats me for about 30 minutes until I give up and make my husband try to rock him. He just screams for about another hour until something clicks and he nurses back to bed. Two weeks prior to this he slept 10-12 hours straight for other family members who babysat him while we were on vacation. Things were fine for two weeks and then this started. This is like the fourth night and I seriously can't take it anymore. As far as we can tell he isn't teething or sick. If you have an suggestions, advice, or explanations for this, I would really appreciate it. Thanks!