How many sets are you doing now?
The intensity at which you do your sets will determine how many you can crank out. I'm pretty much bushed after 12 for large muscle groups, 8-9 for small groups. Some people will say that even that many is too many, but others will say it's not nearly enough. Basically, it comes down to how long/how many sets it takes for YOU to completely fatigue YOUR muscles. There are so many other factors involved, like what type of sets/reps you are doing, etc. Doing forced reps, negatives, drop sets, etc will make it harder to do more sets.
Anyway, I'm no expert - that's just some of the stuff I've picked up on these boards - you should check out the training board as well.
Why don't you just carry MORE of those bags of chicken around? Invest in a mini cooler bag. Or make up some oatmeal and egg white pancakes in the evenings, or on the weekends, and carry those around - they're tasty and full of protein - a quick search on the diet or women's board will turn up tons of recipes for them. They're easy to make, too.
Use flax seed oil or peanut butter for healthy fats - the type of fat in steak or whatever isn't so good.