anything that would help me loose more weight?!

I weight 230 and I want to loose about 30 lbs and I'm finding it a little challeging due to not having enough time to exercise, I work two jobs (70 hours a day) were Im sitting all day long, the only time I have to exercise is beetween my breaks and lunch wish I do walking on the parking lot. I eat every morning a shake made of yogurt, fresh fruit, milk and a scoop of whey protein(20 grams). Lunch a sandwish with some ships, all I drink is water and Lipton green tea without sugar, snack on quinoa crispy bar and beef yerky and at night I drink a cup of milk with penut butter and jelly sandwish yet I find it hard to loose weight. I want to loose 10 lbs a month but instead Im loosing 5 lbs a month. Any help or advice will be apreciated.