How to stay motorvated when unfairness playes its hand?

my family looses weight really slow like mum went strictly on weight watches and walked fast a hour a day ofr weeks and you couldnt see a difference and i went on a great diet with lots of walking hard out for 2 weeks and weighed myslf to see if it was worth my while continueing, i lost 1cm from my tummy after busting my *** walking with a water bottle foe 2 weeks so i went to the shop and brought crap and gave up the diet as i thort hell at this rate ill be 60 by the time i get to my goal weight! how to keep motorvated?