One stick of string cheese. Peel it apart slowly, eat it in strands. Sometimes this is all you can manage.
The act of peeling string cheese slows you down, which is good. Small, slow bites. This counts as eating — do not feel guilty if this is all you have.
Keep a multipack in the fridge drawer. Babybel cheese is another good alternative.
No good dairy-free equivalent for this one. Try edamame pods for a vegan-friendly grab-and-go option instead.