Hi there, Santalua!
i just have a couple of thoughts for you off the top of my head. First, I don't know what your walking is like, but check to make sure that your cardio is therapeutic (that you get your heart rate up enough). The best way to burn through calories is to get to about 80% of your maximum heart rate (220 minus your age). Lower intensity for longer periods of time (past half an hour) could also burn fat; lots of different opinions out there, but try checking your heart rate to see where you are.
Second, I have become a big fan of zig-zagging calories. The idea is to have the same amount weekly but to vary it significantly day to day to prevent your body from getting used to the same thing, so your metabolism is constantly working to adjust. Here's a website to explain it; put in your info and it will give you the calories you need to maintain, lose slowly, or lose quickly. Good luck!!
Calorie Calculator - Daily Caloric Needs
I have done this for the past week; it is very adaptable and it helped a lot.