Good question. For whatever it's worth, I have the opposite problem. I'm acutely sensitive to almost everything that I eat. It's a part of my DSI (dysfunctional sensory integration). I feel a little better if I have total control of all of the ingredients, and make it myself, even if it's essentially the same thing, day in and day out.
It'd be fun to be be able to eat out more often. But at times, Restaurant Roulette has a nasty payoff. And I'm not saying that all restaurant food is bad. For me, it's more like tip-toeing through a minefield.
For I were in your shoes, I'd ask: Which 'outside foods' do I eat most often? It's very possibly that your body is saying: I need this particular ingredient that's not in the house. It's also possible that that ingredient is not 'politically correct', but something that's helpful for your well-being nevertheless.
It's also possible that the cooking and clean-up are very unfun for you. If that's the case, I'd do one of two things. Continue eating 'outside food' every day, but without beating yourself up. Or simplify your home-cooked meals, so that the preparation and clean-up don't take as much time.