I would see a gastroenterologist and be totally honest with him about your history so he knows how to treat you. I would also ask your doctor for a referral to a therapist experienced in working with eating disorders. I don't advise going on a diet of any kind at this time because diets are a trigger for your eating disorder. At this point you need to recover from your eating disorder more than you need to lose weight. I know that's hard to hear. I would just work on eating healthy and reducing carb intake and as a result of this you will naturally lose weight at a slow pace which is what both your body and your eating disorder need. You need to get healthy, emotionally as well as physically. Regular non-intensive exercise such as walking can also help your health and your mood as well. Many of us with eating disorders also have problems with depression so regular exercise is good for that too. Your therapist may or may not recommend medication for depression. As hard as this may feel, accept who you are, and at least for now that self with all its wonderful characteristics is enclosed in a body larger than you would like. That doesn't alter who you are. I have a friend who is very overweight and she spends a bit more on her clothes at specialty stores but she always looks beautiful. Don't wear ugly "tent clothes" to hide under. Wear flattering attractive styles in nice colors. Hang in there, it will get better.
I understand how you feel, I am bulimic and at one point was binging and purging up to 6 times a day. ALl I can tell is to get professional help as this condition can do a number on your body. I have resorted to self help, but it truly becomes an addiction and even though its not helping you lose weight you continue to do it. MY advise would be to see a personal trainer if you can afford one and get on a good meal plan. I like Jackie Warner's Book or the abs diet for women. These are great for lifestyle eating changes. Other diets that don't provide all your nutritious needs can be a crash and burn situation. Counseling and incorporating healthy habits into your life is what helped me. Hope this helps, I know its a struggle but you are doing more damage the longer you do it. My vanity was also a reason I have gotten better, I didn't want my teeth rotting out of my head.