A 29-year-old man comes to the office because he is “worrying all the time.”  The patient has a long history of anxiety and says, “It was manageable when I was allowed to work from home, but since I was promoted and have to come into the office, I’m completely overwhelmed.”  He spends hours rehearsing before meetings to find “the right words” to say and repeatedly edits emails until they are “good enough.”  The patient also has difficulty leaving the house in the mornings because he spends 1-2 hours making sure all the appliances are unplugged.  He shares, “I know it sounds crazy, but when I’m at work, I constantly worry that there will be an electrical fire at home, and I can’t concentrate.”  Physical examination shows no abnormalities.  On mental status examination, the patient describes his mood as “really anxious”; he is restless and makes poor eye contact.  Which of the following is the most likely diagnosis?