Why the waste of time

Why do we waste our time to do dieting when it wont work let me tell u about my experience.
By the end of 2009 i weighted 98 k so went to my deitian n we worked out an eating plan because i had anaemia, womb infection and ucler so i started my deiting and because i was i vegetarian it was not easy but i tried to do form exercising to following my deit plan so checked my weigh again after six months of deiting and exercising and i was shocked to know that after all the time i spent i have gained extra 3 pounds more so i continued and this time it was more than what i did before and now i weigh 110k so now i asked my self why did i waste my time on deiting that wouldn't work and i know there are people out there with the same problem and it all came down to eating breaskfast in the morning so am with my current weigh am try a new deit plan this time i am doing it my way and in six months time i will let u know what happens and if u being through this let me i will appreciate it if u let me know.
P.S thanks