weight loss

i really would like to lose weight & fat but i crave chocolate and sweet food ALL the time, and i tell myself not to eat too much of it but i can't control myself and i just eat it all, which makes me feel terrible after. i also usually always drink powdered sugar drink ( eg raro, koolaid ) and i want to change to water but i just crave the powdered juice, does anyone have any suggestions to control the cravings and exercises that help list weight and fat? :-)