I'm painting a room that will be our nursery. i'm using No VOC primer and paint to protect my wife and child from toxic fumes.

then it all went bad.

First the room was painted a dark blue and black so the primer I used didn't cover the blue until the 3rd coat of primer in four days. I thought i allowed the coats to dry enough before the next coat. 24 hours between each coat.

second, our house is old and has horse hair plaster. i looks like the previous owners papered over the plaster before painting it the dark blue.

as I was putting on my 3rd coat of primer and wishfully thinking my last. the wall started to bubble.

lastly. instead of leaving it alone, I started picking and scrapping the wall that was bubbling and pulled 60% of the paper off one wall. I think if I didn't stop i'd destroy all the work I'd done. right now only a small wall section has been scrapped down to the horse hair plaster.

so my question is. Where do I go from here?
1. how to i repair the section of wall that i peeled back to the plaster? not all the paper is removed.

2. how to a treat the rest of the walls so this doesn't happen there?