Perhaps some kind of salami-bar could help. I usually take 2 with to school.
Sometimes I take a pack of cottage cheese and almonds with me.
On rare occasions I also pack in some berries.
How about a can of tuna? Or some
breaded chicken? There are lots of possibilities.
If you're not living the low-carb lifestyle and just want the protein you could make a (whole grain) turkey sandwich with eggs.
Hope that gave you some inspiration... I'm feeling uncreative at the moment
See ya!