Im wanting to loose weight....?

Hi. I'm 18 years old and I am about 11 stone and my height it 5'3. I am a size 12 in jeans. Size 12 in tops but that's because I have really big boobs size GG. I really am wanting too loose weight. I've tried many of time but I just haven't got the will power. It is getting me so down. I want to have confidence. I hate being the weight I am I really do. Can someone give me a plan to help me loose weight. Lately I have been really hungry and just keep eating I am not pregnant I know that for a fact. Its scaring me now because I don't want to put on weight. I hate running but try my best to do it just hurts my busts. So I have to hold them. Please can someone help me I've done today before about 15 minutes of running and 20 sit ups and I'm not going eat from now till tomorrow. I'm just going to drink water. Please can someone help. Thanks