Hey Montana! That walking will certainly do you good. As a matter of fact, for some folks (me included), exercising when I'm frustrated or cranky or down takes away the urge to eat and puts me in a better mood. Know your triggers, avoid them if you can, and if you can't, have another plan in place to help you deal with them.
Also, once you start to see some changes, your motivation to control your food should increase. Keep in mind that it takes several weeks to form a habit; it won't always feel this hard