Am I dreaming, or is my weighing scale broken? PLEASE ANSWER DESPERATE?

I am the type of girl who's very insecure about her weight, mostly because I have been fat half of my life. One day I got the chance to get skinny, and I vowed to keep it that way. When I went into my new school, things got really stressful and it made me snack on a lot. This made me gain weight, but I didn't care (My skinny weight was 47kg and my present weight is 52kg). That is until I went to Australia for a summer (winter) vacation, and found out that aussie's food are AMAZINGDELICIOUSICANTSTANDBEINGINFOODHEAVENIAMEATINGUNICORNFOODALTHOUGH THEYAREFREAKINGEXPENSIVE. I wasn't really aware of my weight back in aussie because I did't have a weighing scale handy. When I reached home, I sprinted into my bedroom and stepped on the weighing scale... And holy moly, I turned into a 55kg. I started having nightmares, and I really need to loose weight before 25th of july. I decided that I should loose 7kg (I know its not healthy but I am determined to do it). I finally decided to use duromine every two days. Yesterday was my first day of taking one, and I dropped 1 kg. Then... This morning I tried weighing myself and I was back to 54 (10 am) then at 1 pm I tried it again and I was 52 and a half kg then at 10 pm i tried it AGAIN because I was overjoyed, but it turned out I was a 55 again. Now I only ate an apple today, and yesterday I ate 5 pieces of salmon makis. THATS IT. is my weighing scale broken, or am I just dreaming and this is all just a nasty nightmare? (i hope) Sorry for the ultra long post...