Solitary (2009)

When Sara Ballard becomes trapped inside her suburban home by agoraphobia, her fear becomes a nightmare when her husband mysteriously disappears. With her sanity pushed to the breaking point, Sara's only hope lies with her estranged sister and an enigmatic psychiatrist, Dr. Reznik. But can they be trusted? Sara's journey through her darkest fears takes her from one unexpected revelation to another, and ultimately to a shocking conclusion beyond her imagination.