real problem with weight, please help :(

Question

HI :)

while I'm at the take off, and I weigh myself every day, it is that if I eat breakfast toast with jam and drink water and eat Turkey fillets, I on a day 3 kilos! have less.
But if I a half chocolate eating, I guess these 3 kilos just dinner to :(is it only with me? What am I doing wrong? thanks ;)