The Perfect Son by Lauren North
Tess Clarke wakes up in the hospital. She's been stabbed and her son is missing. As she tries to recall the days leading up to her stabbing, she fears police are not doing all that they can to find young Jamie. To rescue her son, she needs to recall everything that happened before and on the day of Jamie's 8th birthday.
I did have my suspicions regarding the big mystery of where Jamie was, and that proved to be a correct assumption. Meanwhile, the situation with Tess's brother-in-law and her grief counselor were so creepy. As those storylines progressed, I was thoroughly creeped out and angry with and even for Tess.
The tension in The Perfect Son does have you on the edge of your seat. I hated being interrupted. I just wanted to sit and read it in one sitting, but that proved difficult when there were chores to do and meals to cook. I recommend having time set aside where you can read and keep reading for hours. It's a gripping novel!