So hard to get my willpower back :o(

I'm yo yoing and I'm so very sad! One minute I'm doing good and losing then I'm eating again... now I'm back but trying to get rid of desires to eat so starting with semi atkins. Still under 500 calories per day though! So this morning I had a piece of polish sausage and that's it! I need to go into ketosis so I can successfully get into my fast! Oh please provide me with some encouragement for I burst out in tears! I looked in the mirror and I'm so unsatisfied with what I see... I'm about to have a bar bQ and family and friends will be seeing me after some time... when I was much thinner and it's two weeks away :o(

Is this possible? To see an improvement in two weeks? Please tell me this is possible