It sounds like logging the films on Letterboxd makes watching movies feel productive, so you feel less guilty spending time watching them because it's almost like checking an item off your To Do list. There's an app called TV Tracker I use to keep track of what episodes I'm on, when shows come back, etc. Maybe using that and logging shows will give you the same rush as logging on Letterboxd.

Either way it sounds like you already enjoy watching tv and just need to let yourself relax and watch what you want. :)