I am on Day 3 of no PMO. I have recently started reducing my drinking (I am on the cusp of being a highly functioning alcoholic), and I quit smoking 13 weeks ago.
Quitting smoking was difficult. Making it this far has given me some confidence in tackling alcohol and P.
I also can overeat. I will relate one experience I had last summer, but I would highly recommend talking to a health professional if you decide to explore this route.
This past August, I did a 4 day fast. Water only. Well, coffee - the headaches were too intense the second day, and since black coffee has no calories, it did not affect the health benefits of the fast, and the ketosis that ensues.
There were too unexpected results of the fast. Losing weight was expected, and I also expected to put it back on over the next few months, which I did.
What was unexpected, was the ATTITUDE of GRATITUDE I had when I ate my first bite on Day 5 (a fig from my garden). I had an epiphany that happiness and gratitude are indelibly intertwined, and this was a very powerful realization.
The second was that I ate less compulsively after the fast. Much more thoughtfully. It took months before I found myself overeating late at night, mostly due to stress and (possibly) a loneliness in my soul (I am single now, but I have had this feeling even when in a relationship).
I am not recommending you try a fast, I am simply relating my experience to you. It was quite awful, those four days. You end up in a bit of a feverish sweat, as your body goes into ketosis, and starts burning your body fat. It feels like a flu, and indeed, there is a term like "ketosis flu" or "the fasting flu". So you need about a week to do it. Four days of fasting and doing nothing much (lying in bed a lot, like a flu), and then three to five days to recover, as you will be VERY low energy afterwards.
Good wishes.