This may sound gross until you try it, but one of my favorite sources of protein (and Omegas and calcium) are sardines straight outta the can. It may take some experimenting to find some brands that taste really good/not "fishy", but WOW; once you find the right brand, it's amazing (very filling, VERY convenient, and no irridation from having to use a microwave).

My favorite brand/product is the second one here -
Skinless & Boneless Sardines | Crown Prince Natural. According to the website, they unfortunately do not have any retail distributors in MS, but you can always order online (which is prolly much cheaper).
Other quick/easy food ideas -
Protein Powder (don't think I can ever get enough of TrueProtein's CMDI!!!

)
Cheese
Nut Butter (cashew, macadamia, walnut, etc. nut butters) - straight outta the can (or on something like low carb flax bread, depending on your carb intake)