You dont need instant oatmeal.. Get the big box of quaker oats (non-instant rolled variety) and nuke it for 2:30 with water. You need to add a pinch of salt, and if you like it sweet use honey instead of brown sugar. It is better for you. A big box will be ~$5
As for lunch time, even a power bar will let your body know there is food around. Power bar, goo, some fruit, etc...