Am i overweight? honestly?

I am 16. . i have a 35 inch bust 29 inch waist and 33 inch hips and weigh 123 lb.. and i just always feel so fat.. i hate what i look like i have flab everywhere and my dad always tell me i have legs like tree trunks! this has been going on for ages ever since i was about 9 i hated my body and thought i was fat. When i was at school i would always look around at all the other girls and realise i was the biggest.. i would always go through stages where i got so down i decided i had no option but to do something about it, but no matter how much dieting or exercising i did i never lost any weight so i just gave in.. right now i can feel that im getting to that point again and i just don't know what to do anymore this is making me so unhappy, i cant even sleep tonight im so annoyed with myself!! any help?