I don't get it? please help?

I've searched everywhere and people say 'youre not meant to starve so eat healthy and dont go into starvation mode, but low fat' and then you hear 'eat A LOT and fatty foods to lose weight'? I want to lose weight ( 7 pounds in 2 weeks) I don't know whatthefu*ck to do? seriously help me. So when you're on a diet, are you just not meant to starve, or are you not meant to consume little calories such as 400?? is it about the calories or about the starvation? Please help.