You lose weight by burning more calories than you intake. You have to burn 3,500 calories more than you intake to lose one pound. That having been said, people with more muscle burn more calories due to having a higher resting metabolism. So if you have more muscle, you'll have an easier time of losing weight.
Cardio 5 times a week seems like overkill to me. You want to make sure that you're not overtraining. I'd only do cardio 3 times a week, but its your choice. The most effective times to do cardio workouts are right after you wake up, and after doing a weightlifting workout.
In both cases you want to make sure that you're not burning muscle. To prevent this in the morning, have something with protein, but little to no carbs before your cardio. Examples are cottage cheese, a glass of milk, a scoop of protein powder, or a few eggs.
After a weight training workout, don't overdue the cardio. Your body has already spent its energy, so doing cardio will tap into your fat reserves. But don't do 60-80% of your max at this time, more like 30%, with an incline.
The biggest thing is to get your metabolism up. Eat regularly, don't skip meals, and watch your portions. I've also read that interval training works well. So while doing cardio, do 90 seconds at 80% of your max, then 90 seconds at 60%, then 90 at 80%, etc.