Need Assistance

I have been bad...which makes me ashamed to come on here.  I have let my self control crack, and I am trying to get it patched up.  My friends keep telling me how good i look, and yet i see them making sure I'm eating.  I even had a friend ask today if I was throwing up again...even though Mia and I haven't been together for awhile...I want to got three weeks without food at all...I know the first few days will be the hardest and I need some support.  I have been gathering up a shit ton of thinspiration for the task, but I'm more afraid of my friends catching on.  They all are already so suspicious and I made the mistake of letting it slip what my goal weight is and they all freaked.  It's my fucking body and they don't understand what it's like to be fat...they're all skinny and I hate skinny people telling me it's ok to eat...ugh so annoying.  I have decided that no food shall pass through my lips for three weeks or longer...and i will workout twice a day.  I do have a question...does anyone know how to combat the headaches?  I get such bad headaches that I can't stand it...also should i take multivitamins to stay healthy?  Any assistance would be greatly appreciated.  Stay strong everyone...WE CAN DO THIS...NO ONE CAN FORCE US TO EAT!!!!