How can this be????

You would think by now that I have some type of regiment under control. You would think that beyond all of the ups and downs that I have experienced in the last couple of weeks that I would going over my plato and really acheiving a goal. Well it is very sad to say that I am not. I am very disappointed in myself and really don't know what to do.I began my goal knowing that I needed to include more water in my diet and less sugary drinks. Okay, I have that goal accomplished. I also knew that I needed to watch the food intake and amount of intake daily. I think that I got this one down with no concerns. Then I began to try to mold my body with an excersise routine and started walking about 3 miles in the evening. That was a painful part, but I did it.So what am I doing wrong? I think that I need to see a doctor now to investigate whether or not something other than me being greedy or lazy is going on...  I know that I would have to give anything time to really settle in to work but to bounce as wildly as I have seems very discouraging... HELP ME>>>>>>