Ok - you are not a failure - if you were then you wouldnt be having any good weeks!
You have to decide how much you want to lose weight and then look at whats stopping you. Looking at your thread, I am guessing its that elusive third week - sooooo you have got to plan. organise and minimise your chances of failure. Once you get over that hurdle you will be inspired to continue.
Also, if you don t have much to lose - 2 steps forward and one step back is better than nothing at all! x