Another vote for "that's totally normal". 12-18 months is kind of intense. I thought it was much harder than the so-called "terrible twos".
The inability to communicate well combined with still-developing motor skills no doubt is part of the reason why this is such a tough stage. It seems like all of a sudden they go straight from having needs to having wants--which unlike needs don't always work out. ;) Hence the screaming...oh the lovely screaming. Yeah, it sucks...
I did things pretty AP myself--that kind of orientation towards parenting just came naturally to me--and now I feel pretty vindicated for having stuck with it (in spite of all advice to the contrary). DS was a rather sensitive baby/toddler, and had a strong need for closeness and attachment, which I chose to honor (and ignored all the voices saying you're going to spoil that baby by wearing him all the time/sleeping with him/etc). Now, he's three and we have this beautiful, very connected relationship, but he's starting to detach a bit and branch out more on his own, and I feel like having honored his need for attachment earlier helped a lot in working with his personality to make this a positive thing for him. So if AP is working for you, stay with it, you will be glad you followed your instincts.
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