Whats wrong with me???????

i used to weigh 12st and i know i was over weight for my 5ft9 frame, i managed to loose just over 2st,now im just under 10st,but i still feel frumpy n fat,i always pointin out bits that need toned and bits i wana change, ive startin seriously watchin what i eat,and im tryin not to eat anything after 5pm-5.30pm but i feel light headed now, i really want to weigh around 9st,how can i do this properly? i just want to be able to wear nice short shorts in the coming summer n feel y instead of always wearing quarter length trousers :(