I definately agree with the last two posts, there should be no need for you to suffer and you should get help however you must take responsibility for this in terms of your eating addiction whether it may be blaming your doctor, pill or anything else for the way you feel. (deppressed)
I think you have a lot of courage admiting you have a problem and trying to face it.
You have to take control of your life and become the authority, you have to recognise why you feel the way you do and change your behaviour. Whether it is self pity, depression, denial, blamming, negative self talk, resentments, fear and excuse making, these all all things that are affecting you and enabling you to stay in addiction.
When you say " I do well for a while and then it goes down hill" I call this "white knuckling". In reality it takes alot longer than you think to change your behaviour. I was an alcoholic for over 7 years - It took me just over 2 years to get back on my feet and then I was still vunerable.
In the end I had to realise that I was the one that had choices in my life I had to forget about the alcohol and concentrate on the reasons that I wanted to drink - the same way you have to forget about food and look at why you feel the way you do in life. How is your career, social, love life etc and try to improve them. You have to stop trying to control your bad feelings and suppressing your emotions with eating to feel good.
I'm glad your looking at this with a serious approach because it is what is needed, we only live once and we get no second chances. Addiction can kill and I have seen many people die because of it whether it is drugs, alcohol, under/over weight.
I am writing a blog at the moment which will look into addiction and weight loss, when I have posted enough I hope to share it with you all.
Good luck and remember TALK - its the best way of changing yourself and gaining a insight into who you are, hopefully the people here can help you recognise your emotions and put you back on track.