It's not surprising the dream puts your grandmother in the burned room because it sounds like her loss was devastating.

Regarding the monkeys, do you know if you blame yourself for the abuse on some level? Children do that sometimes.

The room with sex objects may symbolize your attitude toward sexuality, perhaps seeing it as something unclean that needs sanitation. It could also symbolize an internal attitude toward the abuse, like an attempt to "sanitize" the emotions around it so you don't feel them so directly.

-Mike