You have to have nearly woken mom, then the following morning straight out of bed to the front gate and meet the merchant, realize you don't have money and need to find something to sell, then you have to go have a conversation with and get possessed by Doyle, he will give you the strength to move the mirror. Search the attic to find 2 items, one to sell, one to call Doyle, which saves trekking to the basement every time you need his help. You can then return to the front gate and sell the knife then buy the sleeping pills, have breakfast, wait till early afternoon then proceed to moms room and search dresser, replace protein pills with sleeping pills. By the way this is explained in the walkthrough that you can download from the first page of this thread, the link is below the screenshots.