I don't seem to making it work...Need support?

Am 24 yold.Never been too thin in my life but never been too fat either.I was always a normal weighted girl 60-65kg.I was quite active excercising on a normal basis.When I went abroad for studies i put on 20kg with no reason.I just couldn't stop eating.(There isn't any health problem or anything)Then,i finished my studies came back home and lost 15kg in 2 years time with different kind of diets.Then i stopped for a year and was stabilized to 75kg.The last year i am under a healthy nutritionist program.The first 4 months i lost 5kg and now it's been 5 months that i am not following the nutrition given to me and am going up and down,70-75kg.Am excersing regularly as well.My boyfriend is happy with the way i look but i don't feel ok with my self.I need to get my self together but i don't know how.It seems that am not that stressed with my weight any more,now that i am with my boyfriend.But i don't want it to be this way!!!I need to lose 10kg!!!Any suggestions?