Monito went down with Motrin quite well. Up again within the hour. In tears at the thought of another awful night, I gave him 1/3 of a dose of Benedryl when we went to sleep, and that did the trick. He still woke up a few times, but less than the night before and he went back to sleep quickly. H-Mama was up with Pequita and Monito by 8 am, and I slept until 10:30. I feel human again. We'll see what tonight brings, but at least I have a system of last resort if I need it again.
Thanks for the supportive comments. As always, it means a lot to know someone else is out there sending empathy my way.