need advice please

I'd like support because I can't seem to lose a pound. I am now exercizing 5 to 6 days a week. where before I didnt exercize at all. I sometimes replace two meals a day with protein whey powder. I eat or drink (whey) five times a day and it is almost always healthy. For a regular meal, I will have skinless chicken breast, salad (with no dressing) made of mainly baby spinich, cucumbers and chicken as a typical dinner. I have either green tea, or decaf coffee (black). I never have sugared drinks. I either drink water or crystal light. I may treat myself to a 25 cal hot choc with a couple of tabespoons of fat free whipped cream. Maybe I'll have a 100 cal wheat english mufffin and sugar free polaner jam. I eat fiber one cereal and 1% milk or kelloggs weighjt reduction cereals for breakfast.

I also, at least four times a week, do the 3 mile walk found on exercise TV. AND YET, I have not lost a pound in three weeks. I am not overeating or undreating. I am exercizing. I eat virtually no fast food or processed foods. I homemake just about everything we eat from wheat breads to soups. We have no junk food in our house. We make fresh fruit smoothies for dessert on occasion. AND YET, I am not losing any weight.

I am 159 pounds and 47 years old. I am 5'8 inches tall. My ideal weight has always been around 135-140. This extra 20 pounds is tiring and bulgy. I want it off and can't seem to get it off.

I eat my daily suggested calories and I make each cal count. I eat healthily.

Please help with suggestions. I am frustrated and lately I walk into the YMCA wondering what's the point. I don't want to give up but it is getting hard to stay motivated.