My son is two-and-a-half and I have been giving him milk with Acidophilus added since he was 1 and-a-half and he does great on it. I myself take acidophilus every day and it helps my reflux also. I came across the acidophilus milk because when my son turned one, he wouldn’t drink the whole milk but LOVED Yo-J (yogurt and juice mixed) I was worried he wasn’t getting enough of the milk fat, and then I came across 2% milk with Acidophilus added in my grocery store and my son loves it and won’t drink “regular” milk.
The screaming jag was most likely from missing a nap and being over-tired. My son STILL gets that way if he is the least bit tired. He will be inconsolable and scream until he finally falls asleep (if I try to comfort him, he screams more). I wouldn’t worry about the fall, kids babies are built for falling down (learning to walk, crawling on stuff they shouldn’t) Don’t beat yourself up about it.