You sound to me like you are burning out. The only cure I'm aware that works reliable is to quit. Alternatively, reading up about work-burnout could be an idea

You sound to me like you are burning out. The only cure I'm aware that works reliable is to quit. Alternatively, reading up about work-burnout could be an idea. Meditation, working out, eating and living healthy, and being mindful about your thoughts when you're /not/ at work (for example just, dismissing thoughts and feelings about work as "not useful" or asking them politely to go away) could work. If you're too deep in, where the burn-out have many similarities with a severe depression, it's probably safest to see a therapist, like some others suggest.