NO NO NO NO dieting.
Until you decide it is time to have a healthy, EVERYDAY lifestyle, you will probably never feel better. I have been through umpteen cycles of yo yo dieting...originally I lost 30 pounds dieting, but I was so obessed with eating and exercise, eventually I started to binge, and got back up to 170. Finally I realized...there HAS to be a better way.
And there is. It is called exercise moderatley, eat healthfully and moderatley, and most importantly, GET OVER IT. Maybe you are not going to weigh 115 or whatever, not everybody's body is the same. If you are going to go by anything, DO NOT choose weight- pay and have your body fat composition measured. Although I realize that this can also turn into an obsession, it costs more money then the scale and ALSO, a majority of people who treat their bodies right have a healthy body fat composition, even if their weight is "high".
In my opinion, there are some steps you can do to deal with body image issues- because at the core, thats probably mainly what you are dealing with here? I try to focus on my HABITs, rather than my weight/size, and I also try to remember that beauty does not only come in a size 6. I am tired, tired, tired, of society telling women what they need to look like, dress like, and what SIZE they should be. I'm a size 14, and I weigh 170 pounds, but I don't give a **** anymore. I eat well, I exercise- and although I am sure my weight WILL go down and I WILL be happy about it, I also am trying to stay focused on who I am as a person and how I treat my body, rather than my weight.
Alright, I've rambled enough for the two of us here.
Good luck, take care of yourself.