My manfriend has an extensive list of food allergies, so I (indirectly) feel your pain, it is difficult to find safe foods out there. His list is longer than Eaglewalker's!

I second the recommendation for Larabars, which you can find at Wild Oats and Trader Joes, among other places. None of their bars have peanuts, though some of them have tree nuts (walnut, pecan, etc). If you can't eat tree nuts but you can eat almonds (which are in the rose family) then check out the Cherry Pie flavored Larabar.

If you can eat eggs, a hardboiled egg is a good high protein snack. Also, look into nut butters like almond butter. In addition to beans, hummus (made from chickpeas and sesame) is a good rocket fuel. If you can eat hazelnuts, Nutella spread makes good sandwiches (especially in a croissant or in a graham cracker sandwich, mmmm!).

BTW, you mention lactose intolerance, a lot of cheese doesn't have lactose in it. The lactose has all been digested up by the bacteria/fungus used to create the cheese. If you stick to the more aged/dry cheeses (avoid fresh things like mozzarella, ricotta, etc.) you may be able to tolerate them better. If you can't do any cheese, then you may have more of a milk protein allergy. Or, you may be able to tolerate goat/sheep cheese better than cow cheese.

If you go to a natural foods store, they usually have bulk sections and you could mix up your own GORP (trailmix) omitting the peanuts and whatever else you cannot eat or do not like. Also, stores like these typically have pretty clear product labelling describing what they don't contain for people who have food allergies.