Frodo,
You haven't messed anything up. Deviled eggs with mayo, mustard and all are allowed on induction. Just be sure it is mayo and not miracle whip
As far as the salads, well I haven't personally had one of the subway salads but I think I remember you mentioning that it contains sauce? Ask for it without the sauce! Bring your own dressing or ask what the lowest carb dressing is they offer, I'm sure they have a packet of ranch laying around (thats usually pretty safe).. and the taco salad? well you never ate the shell did you?
Ok now breath
you are doing just fine, just try to take a tad bit more time planning meals. Pack your own salad, make large meals with lots of left overs and what ever happened to the chicken? That one can of diet pepsi probably wont even effect you, and if it does, it may only slow you down a tad.. nothing that will throw this WOE out the window.
Now I think you need to take a nice hot shower and head to bed.. a good nights sleep always does wonders